High School Physics Notebook

Units = 1)Base units - single unit to define the seven basic quantities in physics (m ; s ; Kg ; A) 2) standard units - combinations of base units 3) Derived units - standard units renamed

In physics (and almost all the sciences) the metric system is preferred. There are only four standard units we will be using this year. All other units will be called 'derived units' and will be different combinations of the standard units

Galaxy Formation : two theories exist = 1) bottom up - big bang creates only small particles. Gravity causes small particles to acerote into Dwarf galaxies , , Dwarf galaxies gravity attract other dwarf galaxies causing them to collide to form larger galaxies 2) Top Down - small particles acerote into large sheets of gas which then break into large chunks that produce galaxy clusters , , the top down is emerging as the preferred theory by cosmetologist because it more thoroughly explains galaxy clusters , , the first galaxy formed 200 million years after Big Bang

Milky Way Galaxy : our solar system is part of the milky way galaxy, barred spiral galaxy , , "Galaxy" comes from Greek for "Milky Way" based on their observations of a band of white, milky light that appears in a section of the night sky , , not until Galileo used first telescope did astronomers know the Milky Way was a bright band of many stars , , term galaxy originally used to describe view of our galaxies, grew to others once they were described , , impossible to count stars in galaxy, difficult to even estimate *according to NASA, it's between 100 billion and 400 billion

Uranus = 7 th planet - 3rd in diameter , 4th in mass , first Ice Giant - differs from Jupiter and Saturn in that it has much less hydrogen and helium and an ice core rather than rock, blue appearance is from methane in the atmosphere , distinct because it's rotational plane is almost parallel to its orbital plan - axial tilt is almost 90 degrees, has 27 moons - all are thought to be captured asteroids , Voyager 2 is the only probe to visit Uranus and discovered many of its moons, has rings (11) - once thought to be a distinct features of Saturn but common in all gas giants - although Saturn's rings are more visible

Neptune = now considered the farthest planet from the sun - 30 AV (AV=astronomical unit - one AU is equivalent to the average distance from the sun to the Earth {93 million miles} ) , "The Blue Giant" even thought's size/appearance are very similar to Uranus , once had a "Great Dark Spot" like Jupiter's great red spot - a large atmospheric storm, but Hubble discovered the spot disappeared in 1995 (Jupiter still has it's and been observed for over 400 years) , voyager 2 is the only probe to visit, has 13 moons (Triton's the largest)

Sonic Booms and Shock Waves = when V source approaches V sounds then the sound waves build up right in front of the source , , if a source is moving faster than the wave speed in a medium, waves cannot keep up and shock wave is formed , , as the source reaches the V sound, the waves accumulate at a single point referred to as the sound barrier , the barrier actually requires additional energy to break through , , once the object goes supersonic, it is through the barrier, and is actually "outrunning" it's sound waves , , the sound waves create disruptions in the air. As the object travels at supersonic speeds, the sound waves interfere constructively creating a conical shock wave , , the energy of the shock wave as it reaches an observer is heard as a loud sonic boom. A shock wave will continuously trail a supersonic object , , a whip crack is a mini sonic boom

Wave Interactions : waves traveling through a constant medium will change in amplitude only a medium can absorb wave energy and cause damped motion (wave gets smaller until it's gone) , , EM waves in a vacuum are constant , , when a wave meets either a boundary or another wave the wave will change other aspects , , first, look at when a wave meets a boundary between two different mediums. Three possible changes can occur : Reflection , Diffraction , Refraction

qualitative = words, ideas to express = ex. dates , years , motions , mechanics

quantitative = measurements, numbers, relationships , 1/4 cups , 25 mph , speed of light

2=2 IS NORMAL MATH 2+2=4 IS NORMAL MATH , , , we use specific units for a reason

2cm=2 in WRONG PHYSICS 2cm+2in=4cm WRONG PHYSICS , , 2cm = 2 seconds WRONG PHYSICS

specific heat (c) : the amount of heat needed to change the temperature of a material , , English : heat to change 1 lb 1 degree F , , Metric : heat to change 1 kg 1 degree C , , specific heat describes the ability of a specific material to absorb and retain heat , , the higher the value of specific heat means the longer it will take a material to heat up and the longer it will take to coal EX sand on beach, ocean water , , the total heat a material absorbs or gives off is related to specific heat , , this formula is also useful for the method of mixtures (or calorimetry) where 2 known materials at different temperatures are combined and allowed to go to thermal equilibrium

Change of Phase : phases of matter = 1) solid 2) liquid 3) gas 4) plasma (fire) , , changes of phases occur when the molecules in a material have enough KE (internal energy) to break the bonds of each specific state , , state of matter is slightly different from phase of matter. A physical state is said to occur at standard pressure, and is affected by temperature only , , phases are directly influenced by pressure (in reality, phase and state are used almost interchangeably

ferromagnetic materials = show strong magnetic fields (iron, cobalt and nickel plus some alloys like gadolinium) , , Ferromagnetism is uncommon and is a result of incomplete pairing of electron spins which creates magnetic domains within the material , , Electromagnetism = the interaction of electrically charged particles and magnetic fields , , Types of Magnets 1) Permanent -magnetic field stays in the material at all times a) Hard = magnetic field persists for a long time (Neodymium) b) Soft = magnetic field disappears over time (Iron) 2) Electromagnets = magnetic field created by electric current and can be turned on and off , , when a changed particle (q) moves with a certain velocity (v) through a magnetic field (B) it is deflected by a force (f) , , F=qvB or B=F/qv , , NOTE : this formula is only valid when the velocity is perpendicular to the magnetic field , , Geomagnetism = the magnetic field surrounding the entire Earth , , the Earth has permanent magnetic field that acts very similar to a bar magnet , , Tesla is used to describe large magnetic fields , Gauss is used for small fields (like Earth's field) , , Magnetic Field Strength (B) , , Ferromagnetism cannot be responsible because of the temperatures involved (Curie point of iron is 1043 K - outer core T>5000K)

Curie Pt : temp at which ferromagnetic materials lose the ability to retain magnetism , , electric currents from movement (due to rotation) in the liquid iron outer core produces an electromagnetic field - supported by the rotations and magnetic fields of other planets (Jupiter fast rotation-strong field/Mercury - slower rotation - weaker field) , , new theory indicates that mantle interactions with the top of the outer core creates heat flows that produce the field , , magnetic north does not coincide with geographic north , , magnets north also "wanders" moves approximately 1 degree north and 3 degrees west every decade, as well as daily shifts as much as 80 km, then return to normal

the magnitude of the field is represented by field line density (how many times come from the field) the more lines the stronger the field , , the interaction of electric fields can also be represented with the field lines , , field lines can never cross because each point in free space has its own electric field. A crossing of lines would mean that a charged particle at that point is accelerating in 2 directions at once - impossible!! , , , Current : Electric Potential Energy = equal to the work required to bring a charged object from some zero reference location to a point in an electric field , , it is only the difference in potential is relation to the field that is important , , Electric Potential (v) - voltage = the EPE of a charged object divided by its charge , , V is equal to the amount of work required to bring a positive test charge of 1 C from the zero reference point

Electric Current = (I) = the flow of charge , , quantitatively the definition is the net flow of charge per unit time : I=q/t , , the unit of current is the ampere (A) which is equivalent to c/s , , when a potential difference is created between two points a force is created between the + and - terminals. Given a conducting path the electrons will flow from the lower potential (cathode) to the higher potential (anode) this is called direct current , , the current must flow through a conducting path. The amount of current is dependent on the path

Absolute Magnitude = the luminosity (how bright the star is) if all stars were viewed from the same distance away (32.6 ly or 10 parsecs) , , Parsec = combination of parallax of one arcsecond) derived unit to measure celestial distance , , apparent magnitude = how bright a celestial object looks if viewed from Earth , , the diagram shows that the magnitude is based on 2 things : 1) Temperature: the hotter the stars, the brighter 2) Size : surface area of the star determines how much energy it will radiate , , there is a maximum limit to how bright a star can get called Eddington Luminosity. Once hypergiant get too big and bright (like VY Canis Majoris) it will expel large amounts of mass to stabilize , , Nuclear Fusion : fusion= combination of light nuclei to form heavier nuclei that correspond with an energy release , , elements lighter than iron can produce energy via fusion. The combining of light nuclei gives a heavier nucleus with more binding energy than the light atoms, so energy is released , , elements heavier than iron require an energy input to combine

Fusion Processes I. Solar (only real place fusion occurs) - creted by compression from gravity A. Proton - protein cycle (in medium and light stars like ours B. Carbon Cycle (more complex cycle occurring in larger stars) II. Man-made A. Inertial-compression and then triggering by laser B. Magnetic (Tokamak) - compression by a magnetic field and ohmic healing from an electromagnetic source , , Proton-Proton Cycle of Stars = occurs in the solar core (very high density - 160 g/cm^3) and temperature - 15,000,000 degrees K , , the gamma rays emission is 20 McV, but as the gamma rays go from the core to the photosphere (what we see) they lose energy and are transformed into 1000 lower energy photons. Neutrinos are non-reactive and are immediately ejected

Sound and Light : sound = longitudinal mechanical waves produced by vibrations and transported through a medium , , ex. tuning fork vibrates back and forth producing oscillations in the air. the vibration produces a longitudinal wave that propagates outward. , , sound is mechanical, so it must have a transport medium , , sound waves produce pressure fluctuations in the medium through which it travels , , the speed of sound depends on the medium of propagation. , , sound = solids transfer better than liquids, liquids better than gas , , the stiffer the material (high B) the faster the sound travels , , the speed of sound in air is generally accepted as 343 m/s, but this speed is dependent on temperature and humidity , ,

Hearing sounds : acoustics = the branch of physics that specializes in the transmission and reception of sound , , there are many factors that contribute to what a human hears including pitch/intensity/complexity/environment/psychology/physiology , , pitch is determined mainly be frequency (and a slight bit of loudness). In general as f increases, pitch increases and as f decreases , pitch decreases , , the human ear is capable of detecting sounds in the frequency range from 20Hz to 20,000 Hz. This is called the audible range

Refraction : as light travels and meets a boundary of different substances (mediums of transport) usually what happens is some of the light is reflected, and some of the light passes into the new medium and is refracted , , Refraction : the bending of light rays relative the perpendicular of the boundary between two transport mediums , , refraction occurs because light changes speed as it travels from one medium to the next. The speed that light travels in a specific substance is described by the index of refraction (n) : n=c/v WHERE: n=index , c=speed of light in a vacuum v=speed of light in a medium , , the mathematical relation between the boundaries is described by Snell's Law : if light passes through a boundary and then back to the same initial medium (like light through a pane of glass) then the emerging light will have the same angle, but will be offset , , Total Internal Reflection : refraction is dependent on what is called the optical density of the materials. The higher the optical density, the more the light refracts towards the normal , , when light travels from a medium of high optical density to one of lower density the light is refracted away from the normal , , as the angle of incidence increases, the refracted ray gets closer to 90 degrees until that value is reached. Any ray with a higher angle of incidence will not pass the medium boundary, but will be reflected back into the original, denser medium. This is called total internal reflection , , some applications of total internal reflection are : prism lenses in binoculars, brilliance of diamonds, and especially fiber optics , , , fiber optics = the use of multiple internal reflections in a "light tube" to transmit light )and other EM radiation"

Lenses : lens= curved piece of material (often glasses) that refracts light to produce a different image from the object viewed , , lenses like spherical mirrors have a focal length (f) and point (F) where all light rays through the lens will meet , , 1) Converging Lens - a lens that curves outward on both sides (double convex) and causes refraction so the incoming light bends inward , , converging lenses are like concave mirrors. They can produce real or virtual, upright or inverted, and reduced, same size or magnified images. It depends on where the object is in relation to the focal point. Converging lenses have positive (+) focal lengths 2) Diverging Lens - a lens that curves inward on both sides (double concave) and causes refraction so the incoming light bends outward , , diverging lenses produce only virtual/upright/reduced images , , diverging lenses have negative (-) focal length , , sometimes more than one lens is used at a time to produce a lens system. Common uses are microscopes and telescopes. Lens systems can be used to increase magnification on to reinvert images to upright

Venus = sometimes called Earth's twin because it is the closest planet in size/mass/distance but not because it's habitable by people, has a very dense atmosphere that produces large surface pressures, it has dangerous levels of sulfuric acid, the carbon dioxide atmosphere is a "green house" gas and makes the surface very hot (800 degrees F in the daytime) , Venus has the slowest rotation rotation (243 Earth days) which are longer than its years (225 days) , its the only retrograde rotation (opposite of any other planet) , 2nd closest object to Earth (after moon) and 3rd brightest, pioneer and Magellan probes have studied the planet in great detail (The Russian Vega probe even landed on the surface)

Mars = called the "Red Planet" because dust in it's very thin atmosphere gives it a red appearance in the night sky, has largest volcanoes (Olympus Mons is 68897 ft high) of any planet, but none are currently known active, two moons : Phobos and Deimos , Mars Rovers have successfully landed and travelled over some of the surface of Mars in hopes of a manned mission to Mars *the outer planets : gas giants and ice giants , , gas giants = Jupiter/Saturn , largest with rocky core and denser gaseous make-up , , ice giants= Uranus / Neptune , icy cores, thinner gaseous outer layers

Electrical Power : the general equation for power is P=W/t , , but specific to an electrical circuit, the work done is equivalent of moving a charge through a potential difference , , often resistance losses (bad resistance) are expressed as electrical power loss and are called joule heat or I^2 R losses , , household electrical systems are generally wired for a constant voltage of V=120-V . Electrical appliances are rate by power (Watts). Electrical protection devices in the home are designed to control current (20A circuit breakers are common) , , some residential loads have very high power ratings (>4KW) to reduce current these devices are usually wired for a voltage of V=220-V (with special plugs and sockets) , , electric companies do not charge for power, but for electrical energy (work) consumed. The typical unit found on electric bills is KW-hr (P*t) *electrical power in the US (and almost all countries) is AC not DC but as long as average power is being discussed the formulas and applications are identical*

Magnetism = the force created by the flow of electric current in ferromagnetic materials , , Lodestone = naturally magnetized rock , , magnetism shares many characteristics of electrostatics but is actually more similar to current electricity in origin , , Magnets = a material that creates a magnetic field and has opposite poles designated North (N) or South (S) instead of + or - , , pole force law- like magnetic poles repel and unlike magnetic poles attract , , poles always occur in a opposite pairs called magnetic dipoles (single poles have been terrorized but have not yet been isolated) , , magnetic field = (B) a vector quantity describing both the magnitude and direction of the field surrounding a magnet , , magnetic fields are caused by moving electric charges, not static , , magnetic field lines represent the direction/strength of a magnetic field 1) the direction of the field is tangent to a line at any point on the field 2) the number of lines per unit area is proportional to the magnitude of the field

-Gas/Ice Giant (Jovian Planets) are mainly hydrogen/helium with traces of elements , , Frost Line = the point in the solar system beyond which gas can form ice crystals and accrete into planets , , Solar Wind = stream of charged particles flowing outward from the surface of sun , , the frost line is between Mars and Jupiter and separates the terrestrial and gas planets. Also, solar winds blew away a lot of the lighter gases from the inner planets. So the outer planets had more mass to start with to attract lighter gases and were able to keep them. That is why they're bigger , , Each individual planet has specific characteristics that are a result of how they formed, location in the solar system and activity on planet

Mercury = closest to sun, smallest planet in both mass/size , slow rotation (every 59 days) , smallest axial tilt , , axial tilt - the angular rotation between the axis of rotation of a planet as compared to the plane of rotation around the sun , , highest orbital eccentricity (e=0.2056) of any planet , , explored by the Mariner 10 probe and due to be visited by the messenger probe in 2011 (it crashed)

Jupiter = largest planet in both mass/diameter , almost big enough to have become a second star (80 times bigger would've created a star, believed to have a rocky core surrounded by Metallic hydrogen (superhot - 20000 K , pressurized - 4 million atm, liquid hydrogen) , surface is gaseous , it's gas gets denser and more highly pressurized the deeper you go into the planet, fastest rotation (9.8 hours) causes powerful (10x stronger than Earth) and complex magnetic field , the fast rotation and gaseous nature also flatter Jupiter at the poles and make it bulge in the middle (making it an oblate spheroid) , currents has most moons (69) , its 4 largest are known as the Galilean moons (named after Galileo who first observed them with a telescope), the Galilean moon Ganymede is the largest moon in the solar system, the others are Lo, Europa, and Calisto , the other 65 moons are much smaller (combined only 0.003% of Mass) , Jupiter also has rings, but much smaller and fainter than Saturn's

Saturn = best known for it's system of Rings - composed mostly of small ice crystals , origin is still unknown but it has been hypothesized that they are either old leftovers from the planets formation or a newer collision of one of the moons or the remnants of a comet, the rings are around the equator and stay that way even as Saturn's axis changes with respect to the sun, similar in composition to Jupiter, 2nd largest moon - Titan - and a total of 62 moons, many probes have analyzed Saturn and it's rings

standard units of measurement 1)distance (meters) 2) time (seconds) 3) mass (kilograms) 4) electrical current (amperes) - this is the accepted unit, the real standard unit of fundamental charge is the coulomb , , , sometimes it is necessary to convert from one unit or unit system to another. For this to be done, the proper unit conversions must be used. For example, in the US most cars used miles per hour (mph) while standard units are meter per second (m/s)

an interval defines the area between any two points , , displacement - the measure of the net distance, or direct distance traveled as a result of motion -displacement involves both distance and direction from a starting point -displacement is a vector quantity since it involves direction -distance is a sector quantity

Parallel Circuit : a circuit with 2 or more paths for current to travel , , since there are multiple paths for current to flow, resistors determine how much current flows in each path , , because circuits are closed loops, the voltage through each loop must equal the source voltage, so the voltage drop through each resistor is constant , , the total current in the circuit is found using Ohms Law , , also since there are multiple current, the current through each resistor must be found , , the sum of the currents through each path must equal total current , , parallel circuits are much more common and useful that series circuits. The outlets and electrical equipment in hopes are parallel. This gives a standard voltage for appliances to run on , , only current changes

complex circuits : 1) resistor arrangements (>3) with both series and parallel elements 2) multiple voltage sources 3) elements other than resistors in circuit (capacitors, inductors, transformers, etc) , , , circuit protection 1) fuses 2) circuit breaks 3) ground fault interrupters (GFCI) , , fuses burn out and must be replaced ,, circuit breaks - reusable : runs on electromagnet , , GFI- reusable - used locally at outlets and appliances

Momentum (p) = property of all moving objects and is defined as the product of mass and velocity p=m*v , v=vector quantity = magnitude and direction , , when you catch a ball, you must apply a force to stop , , forcing a change in motion therefore momentum changes , , changing time to change of motion of object also changes momentum , , increasing time, decreases force , , weight changes, mass is constant , , weight is due to gravity

impulse = change of momentum when an object has a force over an interval of time , , law of conservation of momentum (LCM) = total momentum in an isolated system is conserved -total momentum of 2+ objects is the same as it was before a collision , , 2 types of collisions: 1) inelastic collision = 2 or more stick together after collision ex. really bad car accident 2) elastic collision = 2 or more bounce off each other after collision ex. billiard balls *momentum is conserved*

velocity = both speed and direction , , , acceleration = value and direction , , , when an object undergoes acceleration, it's velocity changes , , , positive acceleration = same direction as motion and increases velocity , , , acceleration can be change in speed , , acceleration can be change in direction , , acceleration = rate at which velocity changes with time , , you can constantly accelerate while never speeding up/slowing down , , uniform circular motion has centripetal acceleration , , even if you move at a constant speed in a circle, your direction is always changing so you're always accelerating , , velocity is always changing, even if its speed doesn't change , , the average acceleration over a given time interval can be calculated by dividing the change in the object's velocity by the time over which the change occurs , , small acceleration = velocity is increasing gradually , , large acceleration = velocity is increasing more rapidly , , straight-line motion = positive acceleration/ increasing velocity/speeding up , , straight-line motion = negative acceleration/decreasing velocity/slowing down , , an objects speed can be found with speed vs time graph , , straight line on speed vs time graph means speed changes the same amount throughout = constant acceleration , , slope of a straight line on a speed vs time graph is equal to acceleration

force is referred to as an action exerted on a body or object in order to change a bodies state of motion or rest , , push or pull that causes motion , , force is a vector quantity, therefore, has magnitude and direction , , SI units : Newtons (N) = named after genius physics and mathematician : Sir Isaac Newton , , four fundamental forces : 1) force of gravity 2) strong nuclear force 3) weak nuclear force 4) electromagnetic force , , , atom is made up of : electrons , protons , neutrons , , electrons are negative, protons are positive , neutrons are negative , , atomic number = number of protons/electrons , , average atomic mass = number of protons plus the number of neutrons , , isotopes : are atoms of elements with the same number of protons but a different number of Neutrons, same atomic number but different atomic mass than what's in the book , , , radio active decay neutron in a nuclei changes into a proton and electron emitting energy

1) Reflection = the wave bounces off the boundary and changes direction. The boundary may also absorb energy ex. sound - echo ; light - mirror a)if the wave is mechanical and is free to move at the boundary, then the reflected wave looks just like the incoming wave b) if the boundary is fixed the reflected wave is inverted (upside down) 2) Diffraction - as a wave approaches an obstacle or opening , the wave will bend at the edges (the amount of diffraction is dependent on the wavelength of the incoming wave and the size of the obstacle/opening) a) obstacle- the wave bends inward around the edges b) opening - the wave bends outward from the edges 3) Refraction - the bending of waves at the boundary of two mediums with different refractive indexes , , refraction requires 3 things : a boundary between two mediums of different refractive indexes , , a boundary that allows transmission of the wave through the second medium , , hitting the boundary at an angle , , Light Properties of Matter 1) Opaque - reflects only 2) Translucent -scattered transmission of light -no clear object seen 3)Transparent -full transmission -clear image , , waves can also change when they meet each other waves are not like matter. When matter meets a collision occurs and the objects change velocity. Waves will interfere with each other instead.

interference of waves creates many effects, but we will look at three : 1) Thin Film Interference : occurs when light reflects off the top and bottom surface of a thin layer , , may be constructive (brighter reflection) or destructive (no color reflected) depending on the refractive indexes of the film and the surface which the film covers 2) Beats : sound waves that have only slight differences in frequency will produce alternating constructive and destructive interference (sound will get louder and then softer repeatedly) , , as musical notes are defined by a specific sound frequency instrument tuners use turning forks at the correct frequency to see if the instrument has the same frequency - or is "in tune". If the instrument is "out of tune" beats will be heard. 3) Standing Waves : if a wave is reflected from a boundary at just the right frequency it will create constructive interference and destructive interference , , it appears that the wave is just standing still, but that is an illusion. The wave is still moving through the medium, just at the correct wavelength to create the standing wave. , , Points of destructive interference are called nodes. Points of constructive interference are antinodes. , , The number of antinodes is determined by what is called harmonics. One antinode is called the first harmonic or the fundamental frequency , two antinodes is the second harmonic, and so on

Acceleration = acceleration happens when an objects velocity changes. It is the rate at which velocity changes with time. ex. changing speed - slowing down and speeding up -acceleration can also be a change in direction -acceleration is the rate at which velocity changes with time. Velocity includes speed and direction , , so an object accelerates if speed, direction, or both change -uniformed circular motion = has centripetal acceleration - means the change in direction is the cause of acceleration EX. Ferris wheel , merry-go round , , , velocity = V (meters / second) , , time = t (seconds) , , position (distance) = d or x (meters) , , , acceleration = a = change in velocity / time , , , acceleration is a vector quantity = includes direction

negative - acceleration is going opposite of motion , , , g= 9.8 m/s ^2 = otherwise known as freefall acceleration , , freefall acceleration describes the rate at which ALL objects fall to the Earth , , , without gravity - things fall at the exact same rate = 9.8 m/s ^2 down , , , acceleration due to gravity is the most constant form of constant acceleration , , constant = only quantity that does not change or stays the same , , constant acceleration = stays the same during an entire interval of time

The structure of the solar system follows the Newton's law of universal gravitation , , gravity is a field force caused by the interaction of masses. motion is dominated by the larger mass, which is why the sun is the center of the solar system and the rest of the planetry orbit it , , the sun is almost 746 times bigger than the combined masses of all the planets. That's why our solar system is heliocentric (sun centered) , , for thousands of years astronomers thought the universe was geocentric (Earth centered) , , planets are considered natural satellites of the sun (Earth is the only known object with artificial satellites) , , Johannes Kepler devised three laws of planetary motion to describe the orbits of planets around the sun : 1st law = planets travel in elliptical orbits 2nd Law = the arc area swept by planets is equal for any, equal time (as the planets orbit gets nearer to the sun the planets speed up) 3rd Law= the farther the planets get from the sun the longer it takes to orbit , , Eclipses = the moon is responsible for eclipses on Earth, which come in 2 types : 1) Lunar Eclipse = when the Earth comes between the sun and moon , happens only when the moon is full-the shadow of the Earth can be seen covering a part (Partial Eclipse) or the entire (total eclipse) moon , , takes several hours for the entire event and can seen anywhere 2) Solar Eclipse = the moon comes between the Earth and the Sun , , happens only with a new moon- moon can be seen covering part/all of the sun , , lasts only for a few minutes and can be seen only for a limited time , , solar eclipses have 2 parts : a) umbra which is a small dark spot where the sun is entirely covered b) penumbra which is only a shadow area, larger

solar eclipses come in four varieties : total , annular , partial , and hybrid , , lunar and solar eclipses occur at about the same frequency , 2-5 times a year, but total eclipses are relatively rare , , eclipses don't happen every month because the moon's orbital plane is 5 degree different than the Earth's orbit with the sun. There are only two points of intersection per month where the Earth-Sun-Moon are all aligned. These points are called nodes , , historically and mythologically eclipses have been connected with all sorts of mystical qualities. Now eclipses are predictable centuries in advance - both types/durations , , Planets : at the formation of the solar system two types of planets appeared based on their proximity to the sun : 1) Terrestrial Planets : four inner planets (Mercury, Venus, Earth, and Mars) composed mainly of metals (especially iron) and rocky silicates 2) Gas Giants : larger outer planets (Jupiter/Saturn/Uranus/Neptune) composed primarily of gas and ice (not always water) crystals , , the terrestrial planets were close enough to the heat of the sun so only material with higher melting point formed the planets. Because these materials are rare the terrestrial planets are small, but dense

temperature = the measure of the hotness of coldness of an object (or more specifically, the instantaneous measurement of an object's internal kinetic energy , , temperature is a scalar quantity so historically it was attempted to remove negative numbers from the concept , , Fahrenheit devised a scale using ice and salt (the lowest temperature that could be produced in his time) , but the results were too unpredictable so his scale was based on the ice point and steam point of fresh water , , , types of thermometers : 1) expansion - first used by Fahrenheit 2) Thermocouple - uses electrical resistance 3) infrared - uses infrared electromagnetic waves , , Celsius also developed a scale but broke it's gradients into 100 degree, so it was called the centigrade scale , , , ice water= 0 degrees C , , , boiling water= 100 degrees C , , , Relative temperature scales = the Fahrenheit temperature scale and the Celsius temperature scale are called "relative" scales because they are based on water

the critical points of the scale : Fahrenheit= ice points 32 degrees F , Steam point 212 degrees F , , , Celsius = ice point 0 degrees C , steam point 100 degrees C , , , advances in physical theory, and improved methods of cooling made the relative temperature scales obsolete by the end of the 19th century William Thomson, Lord Kelvin revises the temperature scales and based it on the new theory of absolute zero , , , Absolute Temperature Scales = based on absolute zero *absolute zero- the theoretical temperature at which all motion of molecules ceases *sometimes called the "Thermodynamic temperature scale

There are 6 simple machines 1) simple lever =long tool such as pole/rod under an object lift it -levers work more efficiently when we add a fulcrum point , , simple machine : 1 input , 1 output , , , pulley = machine consisting of a wheel over which a pulled rope/chain runs, changing direction of pull, used for lifting a load -decreases force needed to lift a load, increasing mechanical advantage , , , fixed+moveable pulleys = fix-pull down on rope/chain = direction of force is reduced by pulled , attached to a stationary , , , movable pulley = free to move up and down typically attached to ceiling or other object in the room by 2 lengths of ropes *more than 1 pulley in system is called a block and tackle system = multiply pulleys

wheel and axel = when effort (input) and resistance (output)are equal, the lever is an static equilibrium , , , inclined plane family = simple inclined plane - ramp , , MA = length of incline / inclined height , , wedge= triangular shaped toll, portable inclined planes (2) -can be used to separate objects or portions of an object , , a thin wedge of steel can create an enormous force for lifting/splitting , , , screw-inclined plane wrapped around a cylinder

work (W) = done when a force is applied to an object and the object moves in the direction of the applied force -calculate by multiplying force and distance the object moves , , work is zero when = object doesn't move (or stops moving), you are not applying a force , , , power (p) = rate at which work changes with time, or how much work is done in a specific amount of time -calculate by work divided by time , , , different forces can do the same amount of work when you increase the distance

"simple machines" machine = an apparatus using and applying mechanical power, and having several parts - each with a definite function and together performing a particular task - the simplest mechanics use mechanical advantage (MA) to multiply force , , multiple types : simple machines and complex machines

Electrical Resistance : Resistance (electrical) - the opposition to the flow of charge (currents usually the flow of electrons) Symbol: R , , for electrical current to flow, the charged particles (q) must have a path to travel. The electrical resistance in the path determines how much current will flow , , the most common conductors of current are wires. the resistance in these wires is dependent on four factors: 1) Length of Wire: the longer the wire the higher the resistance (direct proportion) Symbol : L Units: n 2) Resistivity : the specific resistance of a material to electrical current flow. These values are usually listed in tables 3) Cross Sectional Area of Wire : how thick the wire is. The thicker the wire, the lower the resistance (inverse proportion) , the general equation for resistance at room temperature (T=20 degrees C) 4) Temperature : as temperature goes up, so does resistance , the effects of temperature are dependent on the type of material (like P). this factors described by the temperature coefficient of resistivity , resistance in an operating circuit can be good or bad A) Good- materials that convert resistance into some other useful form of energy , these are usually accounted for in circuits and are represented as "louds" B) Bad- resistance in wires causes unwanted loss of energy, usually heat loss. Not normally represented on diagrams - electrical resistors come in four basic categories :

1) Conductors : low resistance to current (sometimes conductors are listed according to conductivity instead of resistivity (p). 2) Insulators : high resistance to current 3) Semiconductors : special properties of resistance used in diodes , transistors , and chips 4) Superconductors : at very low temperatures, some materials lose almost all resistance and become superconductors , , German physicist Georg Ohm devised another way to define resistance in a circuit called Ohms Law = a potential difference (v) causes an electric current (I) in a conducting path. The relation is directly proportional , , the constant or proportionality between the two is the resistance (basically the path the current takes through the circuit) this constitutes the actual definition of R , , for many materials R is constant through a wide range of applied voltages. These are terms "Ohmic" resistors after experiments done by the German physicist Georg Ohm , , this led to the formula V=IR, which is now commonly known as "Ohm's Law" , , some materials do not follow Ohm's Law and are called "non-ohmic" , , Ohm's Law is used to quantitatively analyze the components and operation of simple circuits

Motion = a change in position , , , mechanics = the study of motion , , , newtonian mechanics = the study of motion below the speed of light , , , distance = the measure of a total change in position

1) English units : feet, inches, yards, miles 2) Metric Units : meters, kilometers, centimeters -distance must be measured between two clearly defined points

Fusion : 1) solid to liquid = melting 2) liquid to solid = freezing/solidification , , to undergo a phase change requires significant heat energy to break the molecular bonds. This is called latent heat , , so the latent heat of fusion is the heat required to change phase from liquid to solid or vice versa , , note : to melt an object requires the addition of heat energy, while freezing requires the removal of heat : also, no temperature change occurs during a change of phase even though heat transfer is occurring , , vaporization : 1) liquid to gas = vaporization / evaporation 2) gas to liquid = condensation , , one rare occasions, certain substances can skip a phase 1) sublimation : going from solid to gas 2) deposition : going from gas to solid Using Heat : thermodynamics = the study of converting heat energy to work , , heat energy (thermal energy) is used for heating, cooling, and transportation. Each way uses heat differently based on the three laws of thermodynamics :

1) First Law - the total heat and work in a system must be conserved - thermal energy can only change two things : work or internal energy a. work will cause something in the system to move b. internal energy will cause a temperature and/or phase change (ex liquid to gas) 2. Second law - there are three main ideas expressed by the second law of thermodynamics : a. heat can never be completely converted into usable work - efficiency heat systems is always less than 100% b. heat will not flow from a low temperature to a high temperature without work - basis of refrigeration c. addition of thermal energy tends to make the system more disordered (entropy) the second law of thermal, is one of the most important laws dealing with energy as so much of the world uses thermal energy in their daily operations 3) third law = absolute zero cannot be experimentally reached. Scientists at MIT have gotten very close but the third law prevents absolute zero from actually being reached

Compton Effect : quantum theory predicts that if photons act as particles, they should collide with another mass , , Arthur Compton conducted an experiment where he directed x-rays (high frequency energy) at contained gas molecules (looser bound electrons) , , Compton found that there were two resulting frequencies when the x-rays impacted the gas molecules - one the same as the x-ray, but another at a lower frequency , , he determined that the resulting lower f was dependent only on the resulting angle of the scattered photon , , Compton theorized that since the electron has momentum and energy, that the photon must too , , Visible Light Energy = visible light-electromagnetic (EM) wave in the wavelength range of 390-750 nm (violet-red) , , like all waves, electromagnetic waves carry energy. The energy divisible light is dependent on the power of the source and the distance from the source. , , luminous objects produces their own visible light. The light created by these objects than travels from the object to a point of observation as a spherical front. The objects that the light hit is an illuminated object. There are specific terms to describe the source and what an observer will see

1) Radiometry - the measurement of factors related to EM waves 2) Photometry - the measurement of factors associated with visible light 3) Radiant Flux : total amount of EM, radical produced by a source (total power) in all directions. Most luminous sources produce other forms of EM energy also 4) Luminous Flux Symbol = total amount of visible light energy produced by a source in all directions 5) Luminous Efficacy - efficiency 6) Luminous Intensity = the Candela is a base unit for light measurement in the metric system and replaces the former unit of Canale power , , the power of visible light in a given direction , , a forced light source (flashlight/laser) will have a higher luminous intensity than a light bulb that emits in all directions 7) Irradiance = the measure of total EM energy hitting a surface 8) Illuminance = the measure of the intensity of visible light hitting a specific surface , , dependent on IV (direct) and distance from source inverse square , , can be measured with a photometer 9) Luminance = intensity of light reflected from a source , , specular object will have a greater luminance than a diffuse object *even though visible light uses the special unit of Candela and is considered a base unit of physics, this can still be converted back to former base units of energy (J) and power (W)

The Human Eye : the human eye gathers light and forms images through refraction that convey information to the brain. , , The main refractive component of the eye is the cornea, which produces 70% of the eyes refractive power. The index of refraction of the cornea is n=1.376, so light is bent as it enters the eye , , changing the shape of the cornea is one of the main ways that laser eye surgery corrects eye problems , , the second main component of refractive power for the eye is the lens , accounting for 30%. The lens of the eye is a converging/convex lens , , the cornea and lens refract light and focus it on the retina. Retinal tissue has special light photoreceptors called rods and cones :1)Rods = most numerous and sensitive, but no color sensitive main use is low light/night vision 2) Cones = color sensitive, concentrated in the center of the retina. Used for color perception and day vision , , light hitting the retina is processed by the Optic Nerve which translates light signals as electrical impulses to the brain to give visual images , , because the lens is convex it inverts the image of the retina and the brain must reinvert the electrical signals

Dispersion : the scattering of white light into the different colors of the visible spectrum , , as light passes between refractive boundaries, the frequency stays the same, but as discussed, the velocity changes. , , light from the sun is white light, but when it reaches a boundary of higher refraction, the different color lights are all refracted unequally by the medium. Since angle of refraction varies inversely with wavelengths, red light is refracted least and violet , , this phenomena is most readily seen in a prism, where the sides are not parallel so the light doesn't refract equally in both sides , , dispersion and total internal reflection are the causes of the formation at a rainbow. If sunlight hits raindrops at the correct angle, and the observer is behind the sun (so the reflection comes back to you) a rainbow will be seen

magnetic south differs more than north showing that the magnetic axis is not through the center of the earth , , the differences in magnetic north and true north are described by magnetic destination (variation) , , magnetic north is actually a south pole because compass needles are attracted by the opposite pole , , the Earth also shows periodic Magnetic reversals where the poles shift. We are currently in a weakening phase of the Earth's magnetic field, but this doesn't predict a reversal , , Magnets: 1) Permanent a) soft b) hard 2) electromagnets , , current carrying wire = generates circular magnetic field around wire , , right hand rule = 1) thumb in direction of current (I) 2) Fingers curl in circular field B , , Iron Core Solenoid = put an iron rod inside solenoid to increase magnetic field (B) strength , higher field strength , stronger

Electric Currents From Magnetism = in 1820 Hans Oersted (Denmark) found that when an electric current was passed through a wire it changed the direction of a compass. If the current was stopped, the compass returned to normal orientation , , this proved moving electric change (current) creates it's own magnetic field. It was later proven by Maxwell that the opposite also happens. A moving (changing) magnetic field produces an electric field , , a current carrying wire produces a circular magnetic field around the wire. The direction of the magnetic field can be determined by the Right Hand Rule (RHR) : if the thumb of the right hand points in the direction of the current flow, the fingers curl in direction of produced magnetic field

Coulomb's Law of Electrostatics : Charles Coulomb was a French scientist who described the force associated with interactions of charged particles , , Coulomb determined that force was directly proportional to the charges and an inverse square properties to distance , , using a torsional balance (very similar to the Cavendish experiment he concluded the general relation) (Coulomb's Law) , , this formula is valid for point charges or charges uniformly distributed on a sphere (where r will be constant) , , note the similarity of form to the law of universal gravitation except for the large magnitude of difference in the constants , , the force is a vector and can be attractive or repulsive following the law of charges. To find FvE net, a vector resolution must be used , , like gravity, electrostatic force is a field force whose magnitude decreases to an infinite distance

Electric Fields : because electric force (by Coulomb's Law) is mathematically similar to the Law of Universal Gravitation, it is no surprise that an electric field creates a sphere of influence on surrounding particles analogous to gravity , , an area of charge particles creates a force extending from its source as an inverse square function of distance , , electrostatic is stronger than gravity , , quantitatively, the strength of an electric field is the force experienced by one unit of positive charges placed at a certain point in the field , , Q= large charge causing field q= small charge that enters field , , field line direction is based on the direction of acceleration a positive test charge would have at that point in the field

Electrostatics = study of electric forces between electrically charged objects at rest , , Electric Charge = fundamental property of matter (like mass) associated with the atomic particles protons and electrons , , protons has a positive charge ; electrons have a negative charge ; neutrons have no electric charge and are not significant in electrostatics , , unlike mass that can only be attractive, the different electric charges can be attractive or repulsive. The interaction of charges is described by the Law of Charges : like charges repel. Unlike charges attract , , by convection the charge of an electron is considered the fundamental charge because it is the smallest charge observed in nature (excluding quantum theory which have fractional charges for quarks. As quarks have not been observed outside the nucleus they are commonly ignored in electrical interaction) , , the standard SI unit of electrical charge is the Coulomb. this is a dimensionless unit (like the mole) that was based on observable data. (Faraday didn't observe the fundamental electric charge until later) , , electric charge is the first "quantized" value we had encountered. This means that the total value of charge can only come from integer variables of fundamental charge. , , another useful concept in describing charge is the conservation of charge with states : the net charge of an isolated system remains constant *this means that if atoms in a system (exp. bending) have electron interactions, the oppositely charged ions are produced

Electrification : the process of giving a material a net overall electrical charge 1) Friction : friction can either strip or deposit electrons from one material to another to create an imbalance of charge particles , , friction is a mechanical way to create change from a neutral system 2) Conduction : the passing of charge from a charged object to a neutral object by direct contact , , conduction always produces repulsive charges as the neutral object takes the same charge as the originally charged object , , a conducted charge will remain even after the original charged object is removed 3) Induced Charge : charging at a distance from an extension of a charged object's electric field , , an induced charge will return to neutral if the charged object is removed (with the exception of a grounded conductor) , , induced charges are attractive , , the method of induced charge differs between conductors and insulators : 1) induction of conductions: because conduction have free electrons, a charged object will redistribute the charges of the neutral object 2) polarization of insulations : with insulators a charged object will gain the molecules to give a charge distribution (very similar to polarized bonds)

wave speed- how fast a wave travels through it's environment , , not to be confused with particles displacement (for mechanical waves) as the wave passes , , wave speed can be seen as how fast the next crest of a wave comes , , remember that velocity is v=d/t , so for a wave, the distance between crests is period (T) , , for mechanical waves, the wave speed is affected by the transport medium. In general, the more rigid the bonds of the medium the faster the wave travels , , gases have the most loosely bound molecules and generally produce the lowest wave speeds, while solids are most rigid and have the fastest (liquids are usually somewhere in between) : V solids > V liquids > V gases , , there are exceptions to this rule, and some "soft" solids (like rubber and lead) produce speeds below those of some liquids , , this difference in transport medium is explained by the kinetic theory which describes molecular arrangement of the states of matter , , Electromagnetic (EM) waves can travel through a vacuum and through a medium EM waves are also affected if they travel through matter. Light slows down when traveling through matter. If an EM wave is going through a vacuum, it has a constant speed. All EM waves travel at the same speed, which is most commonly called the speed of light

Electromagnetic Waves : a wave produced by accelerating and decelerating electrons , , James Clerk Maxwell developed equations to mathematically describe the production and transmission of these waves (Maxwell's Equation) , , qualitatively these state: 1) a time varying magnetic field produces an electric field 2) a time varying electric field produces a magnetic field , , as described by Maxwell these electromagnetic waves will be self-propagating because the accelerations of electrons alternately produces magnetic then electric fields that will push the waves through space

Convection currents come in two variables : 1) Natural convection currents - no mechanical means is required for the mass transfer. EX: wind , hot air, ocean currents, geothermal currents (mantle and outer core) 2) forced convection currents = a mechanical means is used to enable or increase mass transfer (can allow movement from a cooler to hotter area) EX: refrigerator, forced air furnace, human circulation, coolant in an engine , , convection is too mathematically complicated to do algebraically , so we will restrict our examination to qualitative 3) Radiation = the transfer of heat by electromagnetic waves , , there are many types of electromagnetic waves, but heat transfer is primarily by wave in the infrared spectrum , , radiation requires no transport medium (so can travel through a vacuum- sun's rays to Earth) , , the emission of radiant heat can only increase surrounding temperatures (the emission tends to cause a decrease in the emitter T) , , radiation is most often described as a rate of radiant heat transfer (P or H)

Emissivity = factor characteristic to a material and it's ability to emit/absorb radiant heat energy , , "e" is a number between 0 and 1 where shiny (reflective) surfaces are closer to 0 and black surfaces are closer to 1 , , emissivity determines both the ability to emit radiant energy and to absorb it , , an ideal emitter (or absorber) is called a "black body" and has e=1 , , the net flow of radiant energy between an object and it's surrounding are dependent on the surrounding temperature (Ts) , , note that cohen there is a thermal equilibrium between the object and it's surroundings the net flow is zero. If the temperature of the object is greater than the surroundings, then the value for Pnet will be negative (which means the object will be losing heat energy to the surroundings) This is a clear indicator that emissivity must determine both absorption and emission , , solar radiation is dependent on the angle of incidence of the suns rays to the earth

when heat is transferred to (or from) an object it changes the internal kinetic energy of the molecules (the molecules move faster or slower : KE = 1/2 mv ^2 , , this energy can be measured at any specific instant in time by temperature , , since heat is thermal energy it can be converted into usable work. Thus heat can be measured in the standard unit or energy the Joule , , science tries to express heat energy in these terms (or kilo joules) but other specific heat units persist. The two most common heat units are : 1) Calories (cal) : 1 cal=4.186 J and is defined by : the heat required to raise 1 gram of water 1 degree C -the food calorie is actually equal to kilocalorie or 4186 J 2) British Thermal Unit (Btu) : 1 Btu = 778 ft - lb and is defined by : the heat required to raise 1 lb of water 1 degree F

Energy Transfer (Heat Transfer) : Heat Transfer = the flow of heat energy that creates a change in temperature -the study of heat transfer can be used to maximize or minimize heat flow , , heat can be transferred three ways: 1) conduction 2) convection 3) radiation , , , conduction = conduction occurs from two materials at different temperatures being in direct contact , , this is the usual method for solids , , the cause of conduction is from increased molecular collisions transferring internally through the rigid bonds of a solid , , the direction of heat flow is always from the area of higher temperature to the area of lower temperature

In 1885, J.J Balmer found that these discrete emissions occurred at only certain times. He found that certain atoms had distinct emission spectrum that acted like a fingerprint. This series in the visible light spectrum was called the Balmer Series, and was later found to extend information an infrared (Paschen Series) and UV spectrum (Lyman Series) , , it was also found that when white light was passed through a relatively cool gas and then a prism that certain wavelengths of light were missing (identified by dark lines in a continuous spectrum) the missing wavelengths of that particular gas were called the absorption spectrum , , we live in a spiral galaxy with central core , , the Rutherford model of the atom and classical mechanics could not explain the spectral lines (nor could it explain why electrons in a centripetal accelerating circular orbit did not emit continuous EM waves) , , Niels Bohr started his approach for an atomic model by assuming that classical mechanics didn't apply to the atomic level. This led to his Bohr Model of the atom

Galaxies : a cluster of millions to billions of stars and interstellar dust held together by gravity , , largest known structures in the universe , , estimated 200 billion to 2 trillion galaxies , , farthest identified galaxy is 13.2 billion ly away. So light from near the formation of the universe is just getting to us from this galaxy , , classified differently, main ways are: 1) Spiral (70%) : dense old spherical core (bulge) often a massive black hole surrounded by spiral arms with newer stars and dust, with a halo of dust surrounding the core 2) Elliptical (10%) rounded with older stars, no arms, very little dust 3) Irregular (20%) anything not like the first 2 and often having no clearly defined shape. Lots of dust and younger stars. Very bright , , sometimes 4th type called SO galaxy (Lenticular) is included, similar to spiral but with different arm makeup , , within galaxies sometimes older stars group together = globular clusters , , galaxies also tend to group together in what are called galaxy, instead of random disputation , , group further = super clusters , , super clusters represent the largest aggregates of mass in the universe, can be billions of ly across

the value of -273.15 degree C was obtained by linear extrapolation of a V vs T plot of an ideal gas and is still theoretical , , the second point for calibration is the triple point of water (273.16 degree C ) and a Kelvin is sometimes defined as 1/273.16 of the triple points of water (the triple point of water is the special point where water, ice, and steam can all coexist) the triple point of water occurs at approximately 610 Pa and 0.01 degrees C , , thermodynamic temperature or Kelvins must be used in all formulas. The Kelvin has the same gradient as a C , but the Kelvin scale is absolute (starts at absolute zero) where Celsius is relative (or arbitrary) this allows Kelvin T to be directly proportional to molecular energy

HEAT : the addition or removal of kinetic energy from the molecules of an object , , the idea of heat (Q), or thermal energy, must be distinguished from internal energy (V). Heat is energy that can be transferred (absorbed or given off) from one object to another, and depends on the temperature difference between objects , , two objects in thermal equilibrium (same temp) will not give off heat, although they still may have significant internal energy , , this difference is known as the zeroth law of thermodynamics which states if two systems are in thermal equilibrium with a third system, then they are in equilibrium with each other

En=n (nf) for n=1,2,3... where: E=energy f=frequency , , this is known as Planck's hypothesis and is commonly reduced to the lowest number for a body to give : Ev1 = h f , , E v1 is called the quantum of energy, and all other energy is an integral multiple of this value for a given frequency , , Planck won the Nobel prize in 1918 for his hypothesis , , Einstein took this one step further and proposed that light being an electromagnetic wave consists of "a finite number of spatially localized energy quanta" that "can only be absorbed and created in whole units" , , a quantum or packet of light was termed a Photon with an E=hf , , Photo Electric Effect = displacement of electrons from a surface (especially metals) when light hits the surface , , this was the first experimental validation of the quantum theory. Robert Millikan was skeptical of the photon theory and set up an experiment to disprove it, and he won a Nobel for it! , , the voltage required to stop the flow of electrons is called stopping potential and is based on the maximum KE of the emitted electrons

Millikan also noted that after reaching a minimum frequency (called threshold or cutoff frequency or fo) no electrons were emitted regardless of intensity (I) , , this conflicted with classical theory on three points : 1) KE max is dependent only on f, not I 2) No electrons for f<fo , regardless of I 3) when f>fo , current is observed immediately, even at low I , , since photons are discrete , they don't depend on intensity for their value. The higher the intensity, the more photons, but the KE max will be the same at low or high intensity for the same frequency , , the photoelectric effect was a clear indicator that energy came in quantum packets. No classical theory could validate the results. The practical effects of it are still being applied today in electric eyes and smoke detectors

Law of Reflection = objects we see fall into 2 categories 1) luminous objects - objects that produce their own light sources (sun) 2) illuminated objects - objects that reflect light from another source (moon) *most objects are illuminated, and what we see is only the image of their reflected light. There are two types of reflections : 1) diffuse reflections - the reflected light rays are scattered due to a rough surface 2) Specular reflection - the reflected light is concentrated by a smooth surface *the image we see is dependent on our line of sight - this is because of the way light rays are reflected , , , , Law of Reflection : the angle of reflection of a light wave is equal to the angle of incidence , , , Light Ray Model Surfaces 1) Full reflection : no transmission = Opaque 2) Partial Specular Transmission (scattered) = translucent 3) full transmission (only a little reflection) = transparent , , , since many rays are striking the surface at the same time , the object we see is the reflected rays in our line of sight. If we change our line of sight, the object that we will see will change dependent on the reflected light , , a diffuse reflection will appear dull because few incident rays are reflected directly back from the illuminated object , , a specular reflection will appear bright and shiny because the incident rays are being reflected directly back into the eye. This is the concept of a mirror.

Mirrors : a specular surface that follows the law of reflection to produce images of objects in the line of sight of the mirror , , there are different types of mirrors, but in general there are three image characteristics that are described for the mirror : 1) Image Location/Type : a) a real-image appears on the same side of the mirror as the objects b) Virtual-image appears on opposite sides from object c) measurements , , do=distance of object from mirror (always positive) , , di=distance of image from mirror (real and di ; virtual - di ) 2) Image Height/Magnification : a) same size-image is same size as object b) reduced - image is smaller than object c) magnified/enlarge - image is larger than object d) measurements , , ho=height of object , , hi=height of image 3) Image Orientation a) Left/Right Reversal b) upright-image is right side up c) Inverted - image is upside down

Louis De Broglie proposed in his doctoral thesis a concept known as matter waves. He theorized two equations that described wavelength and frequency (waves) in terms of mass and energy (particles) , , this means that any moving particle should exhibit wave qualities and vice versa , , De Broglie won the Nobel Prize in 1929 for the wave nature of electrons. He is the only physicist to be awarded the prize for a doctoral thesis (work he did as a student) , , the matter waves De Broglie theorized fit nicely into the Bohr model and explained why orbits were quantized. The orbitals acted as standing waves for the electrons must occur in integer wavelengths to be stable. Electrons are not the some particles centripetally accelerating (and then should radiate EM energy) but a standing wave stretched around the nucleus at different integer wavelengths , , the wave effects of normal matter at not measurable by any device yet created. But at the subatomic and molecular level, the wavelength becomes small enough to detect , , The Davisson - German experiment clearly showed that electrons have wave properties. They used nickel crystals that had crystal spacing small enough to diffract electrons shot through the crystals

Planck's Hypothesis : At the end of the 19th Century, scientists could not explain radiation emitted by objects as temperature increased (radiant heat, x-fer , glowing of hotter objects) , , the spectrum of light emitted was idealized by a blackbody (a body that absorbs all radiation falling on it, and the resulting emission is called blackbody radiation) , , Wien's displacement law predicts the temperature (T in Kelvin) of a blackbody based on the radiation wavelength at peak intensity and a constant , , classical physics predicted that intensity of emitted radiation , , this relation however predicts an infinite amount of energy towards the lower wavelengths. This disparity with experimentation is called the "Ultraviolet Catastrophe" , , Planck took a radical approach to this problem by showing that if energy exists in only discrete amounts, theory would align with experiments

Representing Vectors 1)writing vectors- vectors are represented in writing by the quantity symbol with an arrow over it or a bold symbol a) magnitude- represented by a number and unit ex. 25 km , 12.2 m/s b) direction - there are two methods we will use to assign vector direction a1) cardinal points - based on the compass directions N,S,E,W -any point not a direct cardinal point will be expressed as a combination of two points and a degree (45 degrees NW -we will only be using 8 points on the compass, not 32 (we will exclude bearings like WSW and NNE) b2) Cartesian coordinate system - this is a mathematical system using (+) or (-) signs to show direction 2) Drawing Vectors- vectors can be graphically represented in drawing by an arrow a)magnitude - indicated by the length of the arrow b) direction - indicated by the direction the arrow points

Speed - the distance traveled per unit time or the rate of change of distance -speed introduces the concept of time (how fast) into the quantity -any distance unit divided by a time unit (seconds, minutes, hours) is a speed unit ex. ft/s , mi/h , km/hr -speed is a scalar quantity , , , velocity - speed in a given direction or the rate of change of displacement -the terms speed and velocity are often used interchangeably but they are different -velocity does use the same units as speed

Electrical Circuits : a complete path for electricity to flow that converts electric potential energy into some other useful form , , a complete circuit is a closed loop that connects two points of potential difference , , the main components of a simple electrical circuit are : 1) Voltage Source= source of electrical potential in the circuit provides electrical energy to the circuit. In DC circuits this usually a battery 2) Conducing Path = conductor through which charge can be carried from the voltage source to other parts of the circuit (usually wires) 3) Resistance (load) = part of circuit that resists the flow of current and converts EPE into another form of useful energy , , circuits can be much more complex and have other components, but these basics will be the focus of our analysis , , Circuit Schematic = drawing of circuit elements using specific electrical symbols , , schematics are used to represent the main components of a circuit with symbol ; not the exact placement or appearance as would appear in an actual wiring diagram , , symbols for schematics are fairly standard and can be found in a variety of tables , , NOTE : circuit schematics represent current flow as conventional current. Actual current is mostly carried by electrons, and would be the opposite. This normally makes no difference in the practical use of the circuit.

Series Circuit : circuit with two or more resistors with only one path for current to travel , , simple circuit differs in that it has only one resistor and one path of current flow , , since there is only one path for current to flow, a break at any point in the circuit will stop the current flow , , the total resistance in the circuit is just the sum of all the individual resistors in the circuit , , sometimes instead of a single voltage source (E) there are multiple source (one "battery" is really called a cell, and an arrangement of multiple cells is actually a battery of cells) In this case, total source voltage adds up all cells , , also since there is only one current, current is constant anywhere in a series circuit , , since current is constantly, the voltage in each individual resistor is dependent of the size of the resistor (again following Ohms Law) , , since circuits are closed energy loops, they follow the law of conservation of energy. The energy at the source equals the energy consumed in the circuit (the sum of the voltage drops through each resistor

A second way to group waves is how mechanical waves move : 1) transverse wave : the motion of the particles of the wave are perpendicular to the direction of travel of the wave (basically an up and down motion of the wave) , , transverse waves can only travel through solid medium or at a boundary of two different mediums 2) longitudinal wave : the motion of the particles of the wave are in the same direction as the wave moves (basically a back and forth motion of the wave) , can travel through solids/liquids/gases and at boundaries 3) Surface Waves : a wave that occurs at the boundary of two different mediums and has both transverse and longitudinal characteristics (ex ocean waves) , because of the combination of effects, surface waves travel in a circular pattern

Simple Harmonic Motion - repetitive wave motion caused by only one simple force , , vibration (oscillation) - a single back and forth motion (or up and down) - the basic feature of any wave , , a moving spring or a swinging pendulum are cases of SHM , , ideally, SHM is perpetual motion - the wave should just keep going forever, but in reality friction and other forces will eventually stop the motion , , damped harmonic motion - simple harmonic motion with friction included where oscillations become less and less through time , , shock absorbers in a car are a good example of damped harmonic motion. If only springs were used, the car frame would continue to bounce up and down as the springs try to keep the wheels on the road. Shock absorbers are designed to smooth out the ride by balancing the shock to the car from the road and the bouncing of the driver from the springs. (Different types of cars use different arrangements based on what type of roads/terrain they are designed for)

Solar System : the sun and those celestial bodies bound to the sun by it's gravitational force , , solar system is elliptical in shape , , the sun is the center of the solar system with all other bodies in motion around it , , the solar system is part of the larger Milky Way galaxy , , besides the sun, the solar system consists of these other main features : 1) Planets = a body that orbits the sun that has been rounded by its own gravity and has gravitational influence over other masses in its vicinity , , there are currently 8 planets (Pluto being demoted by the International Astronomical Union in 2006 to a dwarf planet) 2) Moons - natural satellites orbiting one of the planets ,, the planet the moon orbits is the primary planet , , moons must be smaller than the planet and controlled by the planet's gravity , , Ganymede (Jupiter) and Titan (Saturn( are both bigger than Mercury 3) Dwarf planets - current term for a body rounded by it's gravity that does not have control over all masses in its vicinity , , hundreds including Pluto , Ceres, and Eres 4) Asteroids = medium sized rock object orbiting the sun ; smaller than a planet, larger than a meteoroid. Asteroids shown no evidence of an atmosphere or other type of activity associated with comets , , Asteroids are sometimes classified as minor planets , , the main concentration of asteroids is in the asteroid belt between Mars and Jupiter 5) Comet - members of the solar system which usually moves in an elongated orbit around the sun , , a comet commonly consists of three parts : the nucleus/the envelope/coma , and the tail ; but one or more of these parts is frequently missing 6) Meteoroid - solid object moving in interplanetary space, of a size considerably smaller than an asteroid and considerably larger than an atom , , once a meteoroid enters the Earth's atmosphere it becomes a meteor 7) Interplanetary Dust = as the name implies these are small specks of dust floating the solar system

Solar System Formation = our solar system is part of the Milky War Galaxy. It has been theorized that the Milky Way was one of the original galaxies formed from the Big Bang almost 14 billion years ago , , the best estimates put the age of our solar system at 4.6 billion years old. It formed on one of the spiral arms of the galaxy (the iron arm) , , Astronomy is the study of matter in outer space. It is believed to be the oldest science. For thousands of years people have observed the skies and tried to explain what they saw , , the formation of the solar system follows the Nebular Model the basic stages are : 1) Nebular cloud of gases start rotating due to gravity between the particles (there are other reasons also like supernovas) 2) As the gases spin they start to contract at the center and flatten. This is called an Accretion Disk. As they spin, the gases at the center begin to heat up. this is the start of the star 3) Farther from the center, disruptions in the swirling gases causes other concentrations of matter. These are called planetesimals 4) Large planetesimals attract other particles from gravity and collision and form planets which clear the dust and smaller planetesimals from the area , , this is the basic model for the formation of the sun and planets of our solar system

For protons in the sun to reach the right speeds for successful fusion might take billions of years (fortunately there are a lot of them so the reactions are occurring continually) , , man-made fusion cannot wait for the proton-proton interactions so they use a deuterium-tritium interaction , , no sustainable fusion reaction has yet been achieved by man (cold fusion), but the break-even point has been exceeded

Spectral Lines = the excitation of gases (from heat or high voltage) and the light emissions from them had been known in the 19th C . It was a continuous spectrum as predicted by wave theory , , when gases were heated, the light they gave off was directed through a prism, and instead of a continuous spectrum , discrete lines were observed

Heat Engines : any device that converts heat energy into mechanical work -follows the 1st and 2nd laws of thermodynamics -fall into two classifications: internal and external combustion engines 1) external combustion engine - a heat engine where heat transfer occurs at a different location than where work is performed -heat engines are generally operated by specific cycles (processes of heat transfer and conversion of heat energy into work that repeats itself in a specific way) a: Carnot cycle: the first thermodynamic cycle to idealize the use of a heat engine in 1824 b: Rankine cycle: more modern version of the steam engine c. Stirling cycle: compressed gas cycle 2) internal combustion engine - a heat engine where combustion and the transfer of heat energy occur in the same place where work is performed a. Otto cycle: four stroke gasoline engine (the two stroke gasoline engine is very similar to the Otto Cycle) b. Diesel cycle: diesel engine c. Brayton Cycle: gas turbine (jet engine) , , there are several other cycles for specific applications but the previous ones are the most commonly found , , most forms of transportation and most electricity production in the world use heat engines and follow these cycles

TYPES OF WAVES : wave= a disturbance that carries energy through matter or space -waves can be divided into different groupings -one way is based on through what they travel : 1) Mechanical wave: a wave that requires some transport medium to carry the energy (EX water waves, sound, seismic waves) , , transport medium : matter that transmits wave energy through the molecules of that matter , , seismic wave: mechanical waves produced by an earthquake 2) electromagnetic wave (EM or light waves) : waves that are self-propagating and are able to travel through a vacuum (EX light , x rays, microwaves, radio waves) -James Maxwell described EM waves as oscillating electric and magnetic fields (thus electromagnetic) -these waves are grouped in what is called the electromagnetic spectrum -vacuum=an area of space with no matter in it (like much of outer space)

frequencies <20Hz are called infrasonic, and are produced by thunder, volcanoes and machinery *infrasonic waves can be damaging to both the ears and to organs , , frequencies >20,000Hz are called Ultrasonic (used in military/medicine/industry) *dogs can hear in the 50,000Hz range, bats can detect 100,000Hz , , , SONAR = Sound Navigation And Ranging , , Sonar = 1) Active "ping" - sending out high energy ultrasound to detect an object (return signal tells you what's ahead) 2) Passive = just receiving sound input from ambient source , , loudness of sound is basically a human perception but it is directly related to the actual physical quantity of intensity , , intensity - the rate at which energy flows through a unit area Formula: I=P/A , , where : I=intensity P=Power A=Area Units= W/m^2 , , intensity is inversely proportional to the distance from a point source , , the intensity of a sound wave can be related to human hearing by the units decibel (dB) which measures relative sound intensity to what is called the threshold of hearing , , NOTE: the decibel is actually a unitless expression for relative intensity compared to the threshold of hearing , , a second point often associated with the threshold of hearing is the threshold of pain (Ip). This is the intensity where sound produces a painful effect in the listener (around 110 dB) , , intensity of sound is a primary factor in hearing loss , , sound can be refracted/reflected/interfered with to change what we hear , , , 1) Reflection = the bouncing of sound waves from a surface back to the source 2) Refraction = the bending of sound waves as they pass between different mediums 3) Interference = sound waves interfere constructively and destructed as described before

The Human Ear : Ear = an organ used for equilibrium and hearing , , the human ear consists of three main parts (these are mostly the general names for these parts not the medical names) 1) Outer Ear = a) Auricle (Pinna) - the main visible part of the outer ear. Made out of cartilage it funnels sound into the ear canal b) Ear (auditory) Canal - opening in the ear that channels sound to the eardrum that allows the source of sound to be better determined 2) Middle Ear a) Eardrum (tympanic membrane) = a piece of skin covering the ear canal that transfers the vibration of sound waves to the small bones (ostioles) of the inner ear b) Ossicles (hammer/malleus; anvil/incus; stirrup/stapes) - three bones that connect the middle ear to the inner ear , , the three small bones act as mechanical oscillators to increase the intensity of sound to the cochlea through mechanical advantage 3) Inner Ear = the main auditory processing center of the ear a) Cochlea - organ that converts mechanical sound input t0 electrical signals. Primary organ of hearing , , the basilar membrane is the main mechanism to turn mechanical vibrations of the cochlea into electrical impulses b) Auditory Nerve = nerve that transmits the electrical signals create in the cochlea to the brain to be processes into what we hear c) Semicircular Canals = related to balance rather than hearing. Three fluid filled tubes in the three planes of motion and keep balance.

the orbiting of the moon around the Earth is described by phases . phases are caused by how the light from the sun hits the moon relative to the view from Earth , , because the Earth orbits the sun as the moon orbits the Earth, it appears to take the moon longer to make one complete revolution. Thus there are 2 ways to measure a lunar month : 1) sidereal month - time for moon to make one revolution fixed stars, sidereal period : T=27.32 days 2) Synodic Month - time for moon to make on revolution as viewed from Earth , Period : T=29.4 days , , phases are described by the combination of eight terms (as seen from Earth) : new, full, first quarter , third quarter , gibbous , crescent , waxing and waving

The Life and Death of Stars : star= a celestial body made primarily of gas (mostly hydrogen) that emits a spectrum of electromagnetic waves , , from Earth only about 6,00 stars are visible. With new information and images from the Hubble Space Telescope it is now estimated there are 10^21 stars in the universe , , Earth's solar system has 1 star, the sun , , the next nearest star is Proxima Centauri in the Alpha Centauri system, about 4.22 Ly from Earth (Ly=light years; the distance light will travel in 1 year.

Pluto = downgraded to Dwarf planet because of it's moon Charon. It is half the size of Pluto so it has a large gravitational effect. This is the reason it doesn't fit the new "Planet" definition, Pluto and Charon are totally locked in a synchronous orbit, Pluto also has an irregular orbit around the sun. All other planetary orbits are concentric - called the elliptic (same plane around sun) Pluto has an orbital inclination of 17 degrees to the ecliptic, it is now the 2nd largest dwarf planet (after Eres) , it's located in the Kuiper belt

The Moon of Earth = earth only has one natural satellite called the moon , , because of it's proximity to the Earth, the moon is under the influence of Earth's gravity and orbits it rather than the sun. The moon's orbit is elliptical , , closest celestial body to Earth (other than meteors/meteoroids) and is the second brightest object in the sky (Sun is first) , , average distance is about 240,000 miles , , only natural object other than Earth that man has walked on , , so close to Earth that it exerts a gravitational torque which overtime has slowed the moon's rotation so that it's rotation is the same as its revolution - called a synchronous rotation - which is why we only ever see one side of the moon

Faraday's Law = in a circuit one of the primary components is the voltage source that drives the current. For Dc circuits this is often a battery , , in AC circuits the voltage is derived by Electromagnetic Induction = the production of voltage (emf) or current in a conductor using time varying magnetic fields , , Michael Faraday (England) developed a law governing electromagnetic induction which is named after him , , Faraday's Law states that voltage could be produced one of 3 ways: 1) moving a magnet through a coil of wire 2) moving a coil of wire into or out of a fixed magnetic field 3) rotating a coil of wire around in a fixed magnetic field , , AC= outlets , , DC = handheld , , any of these methods creates a force which pushes the electrons in a conductor around creating current. This is the basis for a generator , , generator = device that turns mechanical energy into electrical energy through electromagnetic induction , , the generator has to same basic components as a motor except instead of a single commutator a generator has a pair of slip rings. This produces AC , , generators are the main producers of electrical energy in the world. There are many ways to produce the mechanical energy to drive the generator, but almost all generators produce the electricity the same way. *AC (alternating Current) - produced by Electromagnetic Induction

Transformers : 2 coils of insulated wire wound around a closer (same) iron core to change relative input and output current and voltage , , a transformer uses electromagnetic induction , an input (source) voltage goes to the primary coil. The wires wound around the iron core of the primary coil produce a magnetic field , , a transformer works only in an A/C system, because a time varying electric field produces the necessary magnetic field in the core (Maxwell) , , a transformer maintains constant electrical power (P=VI) , but it mainly used to reduce current in power transmission to reduce I^2R losses , , a common process is for power to be produced at a generating plant at 24000 V , stepped up to 230,000 V at a transmission station, sent to an area substation where it is stepped down to 10,000v then to a residential distributing station where it is stepped down again to 20,000v where finally it's delivered to homes at 120-240v , , because power P=VI=I^2R is constant, high voltages mean lower current and lower losses. Each transformer is based on the number of loops in each coil

Wave Motion = mechanical wave- a wave that propagates through some medium and transfers energy , , pulse- a single moving wave generated by a vibration , , wave train- a continuous series of pulses from a vibration or oscillation (also called continuous or periodic waves) , , a simple harmonic motion will produce a sinusoidal wave train as already discussed , , the actual traveling wave and the terminology used to describe it are slightly different from SHM : 1) Crest- the point of maximum positive amplitude of the wave 2) trough - the point of maximum negative amplitude of the wave 3) wavelength - the distance between any two successive crests 4) frequency (f) - the number of crests that pass any given point in a certain time - Hertz! 5) Period (T) = the time between any two successive crusts T=Period (seconds)(time) 6) Wave Velocity - the velocity of which the entire wave travels (not to be confused with the velocity of individual particles that always travel at a velocity perpendicular to the shine curve) 7) Wave Energy (E wave) - the energy of the wave transferred to particles along the wave path , , important in seismology and oceanography

Waves : vibration (oscillation) - back and forth/ up and down motion , , periodic motion - motion that repeats itself again and again in the same pattern , , simple harmonic motion (SHM) - periodic motion with the simplest restoring forces which can be described by harmonic functions (sine and cosine) ex. spring/pendulum , , some common terms to describe SHM : equilibrium position - the position the object will be at when at rest , , displacement- directed distance of an object from it's equilibrium position , , amplitude (A) - magnitude of the maximum displacement , , period (T) - the time for one complete cycle of motion , , frequency (f) - the number of cycles per second (Hertz [Hz]) , , , where : f=frequency (Hz) T=period (s) F=l/t

order from strongest to weakest : 1) strong nuclear force - opposes the Electromagnetic Force of repulsion between protons = holds together protons and neutrons in the nuclei = strong force and electromagnetic force held the atom together = negligible over a greater distance than the size of an atomic nuclei 2) electromagnetic = 1/100th the strength of the strong force, but is 10^40 times greater than the Gravitational force, can either attract or repel, oppositely charged particles attract 3) weak nuclear force = responsible for stabilizing particles through the process of radioactive decay = keeps center of our Earth warm/hot 4) Gravity = there are some causes where gravity is stronger than the strong point itself (ex black holes) = force of attraction exerted on all matter = Gravitational Acceleration g= 9/8 m/s^2 = most easily observed in behavior of large objects , , , forces can act through contact or at a distance , , contact force = the push or pull of motion when physically touching , , force fields = force exerted between two (or more) objects even though they do not touch ex. magnets or EM force, attraction of gravity

balanced vs unbalanced forces : balanced = no change in the objects motion on Net Force=0 , , net force = the sum of all Forces , , unbalanced = occurs when two or more forces acting on an object and unequal = results in a change of motion , , when there is a net force the object will accelerate in the direction of the Net force , , , weight vs mass : weight= dependent on your acceleration due to gravity = Fg, is the specific name of the downward force caused by gravitational force , , all matter has mass, but its weight depends on acceleration due to gravity , , mass=kilograms (Kg) , , inertia = measured by the mass of an object, response to efforts made to change velocity , , the force of an objects weight can be found by multiplying acceleration due to gravity by an objects mass , , , acceleration * mass (kg) , , Fg = g*m , , Newtons=N

conservation of mechanical energy = individual energies can change, but the total energy remain constant , , the addition of external work (+/-) or an evaluation of E=mc^2 can invalidate the law, and change the total energy value , , closed system - all energy interactions are internal to the system. No energy is added from or lost to an outside source , , open system = energy can move into or out of a system to change the overall energy in that system , , this means that energy transformations may occur, but the total energy must stay constant if the system is closed , , a roller coaster is a good ex of a simple conversion process in a closed system where GPE is converted to KE and then back again repeatedly until the ride stops , , but even the roller coaster isn't a completely closed system as energy leaves in the form of sound/vibration/friction (heat)

conservative vs nonconservative forces : conservative force= a force where the path of travel does no affect work only the initial and final positions -follows the law of conservation of mechanical energy -potential energies can only be described for conservative forces (like GPS) , , , nonconservative force= a force where the path of travel does not affect the overall work , , invalidates the law of conservation of mechanical energy -these forces go along with Work-Energy Theorem that describes net work as a change in energy , , , so the law of conservation of mechanical energy is valid only when conservative forces are doing work and changing PE into KE and vice versa

conduction : Q= heat transferred K= thermal conductivity t= time of contact A= cross-sectional area L=thickness of surface , , , thermal conductivity is sometimes broken into two groups : 1) conductors = heave a high availability of free electrons which allow a rapid conduction of heat (and closely related to electrical conductivity) , most commonly metals , have a high thermal conductivity 2) Insulators = resist the flow of heat energy , usually non-metals , have very low thermal conductivity , a common way to relate how good an insulator is in commercial industry is to use the R-values (or insulation value) The formula is : R=L/K

convection : convection is the movement of heated fluids (liquids and gases) due to volume expansion and density differences , , convection involves mass transfer instead of collisions of molecular particles as in conduction , , where fluid's bonding structures do not lend themselves to conduction, the losely bound mass of fluids is able to move and carry heat , , because fluids undergo volume expansion when heater, their resulting density fluctuates. A less dense fluid is buoyant. As buoyancy causes the heated fluid to rise, it interacts with the colder fluid and displaces it. The colder fluid is forced downward until it too is heated and rises. This is called a convection current.

Newton's Laws = 1st= law of inertia "an object in motion stays in motion and an object at rest stays at rest unless experiment by a net force , , 2nd= law of acceleration , , , Newton's Third law = every action force has an equal and opposite Reaction Force = Law of action reaction , , equal = same magnitude , , action force = the force of club applies on the ball , , reaction force = force the golf ball applies on the club , , forces for action/reaction pairs do not cancel out because they operate on separate objects

free body diagrams : step one : assign orientation and draw a box that represents our object step two: draw arrows in all directions of forces being applied to object, length should reflect size or magnitude (size) of force *force of friction opposes motion* , , step three: sum forces in X and Y directions , , , force applied=force of friction , , , NOTE : you must first apply a force greater than max state friction to start object motion

velocity includes both speed and direction. So an object accelerates if a 1) speed 2) direction or 3) both changes , , , what is the other name for Gravitational Acceleration? Freefall Acceleration , , , Centripetal Acceleration = change of direction with a circular path , , , Acceleration is in the direction of the change in velocity, which points directly towards the center of rotation therefore Centripetal Acceleration is directed along the radius , , , Tangential Acceleration is perpendicular to Centripetal Acceleration , , Centripetal means "toward the center" or center seeking , , * previously- we have been operating when acceleration and velocity are going the same way* , , equation for centripetal - acceleration , , , acceleration of an object in a circle of radius (r) at speed v , , Centripetal Acceleration is greater in sharper turns (smaller radius) and is also greater at higher speeds

graphing acceleration = similar to how you can find an objects velocity from a graph, we can do a similar process to find acceleration , , accelerating = speeding up or slowing down , , positive slope = speeding up , , negative slope = slowing down/decreasing velocity , , straight lines = not accelerating, constant velocity

Wave Motion = wavelength determines the color of light the eye perceives . The shorter the wavelength the higher the energy of the wave. So for visible light, red light is weakest and violet is the strongest , , if frequency (f) is used instead, then the higher number has the greater energy. Gamma rays are the most energetic , , all EM waves in a vacuum however travel at the same speed v=c=3*10^8 m/s. This is often called the speed of light , , the rates of acceleration of the electrons determine the production of the distinct waves in the electromagnetic spectrum , , all electromagnetic waves travel at the speed of light, so the combination of wavelength and frequency must equal the speed of light , , the applications of production of electromagnetic waves are extremely diverse in today's society (EX radio, TV, microwave, x-rays, CT scans, light) , , the speed of sound is dependent on the medium through which it travels , , EM waves are also affected by the medium of travel. While in a vacuum speed of light is constant, when EM waves encounter matter they slow down , , Doppler Effect : the apparent change in the frequency of a wave as observed by two objects in different frames of reference

if a wave source is moving relative to an observer, the observer will perceive a different frequency of the wave than if the source was stationary , , if the motion is towards the observer the perceived frequency will be higher. If moving away the frequency will be lower , , Doppler effect applies to both mechanical and electromagnetic waves , , sonic booms of objects flying at supersonic speeds (speeds faster than the speed of sound) are a Doppler Effect , , gravitational redshift is a Doppler Effect with light. As light is emitted from a large mass (like our sun) the gravity at the mass will slow the light down and make it shift towards the red end of the visible light spectrum. A redshift also occurs if a star is moving away from the earth . several well observed stars have shown this, which has been used as evidence for an expanding universe

relative height is measured from some starting reference position (often the surface of the Earth) that will be the m = 0 mark (origin of Cartesian references) , , , , Gravitational potential energy (GPE) = energy of an object relative to the height of another object , , , GPE can be + or - depending on the relative height without any additional work , , , Elastic potential energy (EPE) = stored energy due to a deformation of an elastic object (like stretching a spring) , , elastic constant (K) refers to the stiffness of a spring - how easily it stretches. a low k means a spring will stretch easily

law of conservation of mechanical energy = -the law states that total energy in a mechanical system must be conserved -this law was called just the law of conservation of energy until Einstein's famous equation E=MC^2 described how mass could be converted to energy and vice versa. This occurs mainly in nuclear systems

strength and physical vitality required for physical or mental activity , , power derived from utilization of physical or chemical resources , , property of matter that is manifest as a capacity to preform work -when work is done, energy is transformed or transferred from one system to another , , , work vs energy = work - object is in motion, or changing position (Joules) , Energy-is present if in motion or at rest (Joules) , , , potential energy (PE) = Joules - energy of position, results in relative position of objects in a system , , , elastic potential energy (EPE) 1) an object that is stretched or compressed, to increase/decrease distance between parts , , , Spring Constant (K) = amount of force required to move a spring a set amount of distance *Hooke's law : F=K*X , , equilibrium = no induction of stretch of compress spring , , , , energy (E) = the ability to do work , , units: Joules (J) - same as work , , energy can take many forms : (potential , kinetic, mechanical, non-mechanical, gravitational, elastic, chemical , fluid, thermal, nuclear, sound, light, electrical

mechanical energy (ME) = is the sum of the kinetic and potential energies in a system that can be converted to work , , as seen in the definition, physics divides - energy into two broad groups : kinetic and potential 1) potential energy - any form of stored energy that can be converted to work , , , mechanical = a human definition of energy that limits the study of energy in a system to those energies directly related to either the motion or position of a mass , , other forms of energy that are from chemical bonding, motion of electrons, or interactions in the nucleus will be termed nonmechanical and are more advanced topics of study

gravitational acceleration g=9.8 m/s ^2 is an average , , depending on location (on Earth) your gravitational acceleration could be more or loss. The closer you are to the center of the Earth, the greater your gravitational acceleration . EX. you feel acceleration due to gravity most at the North and South poles. This is because when the Earth spins, the equator bulges, pushing away from the center and pulling in the North and South poles.

most basic measurement of motion (quantity that gives the least information) is DISTANCE , , the study of motion is called MECHANICS , , difference between speed and velocity is that velocity includes DIRECTION , , for an object to be in motion it must be changing POSITION , , base SI unit of distance METERS

newton = described the relationship between motion and force with three laws , , these apply to a wide range of motion from large to small scales , , Newton's First law of motion - an object at rest remains at rest and an object in motion maintains it's velocity unless it experiences a net force = objects tend to maintain there state of motion - objects change their state of motion only when a net force is applied , , , Law of Inertia = inertia = the resistance to linear acceleration by a force applied to the body = less inertia ,greater mass = more inertia , , moment of inertia = tendency to resist angular acceleration , , ways to take mass : scientific scale , triple beam balance, inertial balance , , scientific/normal scale and triple beam balance uses gravity inertial balance does not use gravity

newton's second law = describes what happens when net force is not zero, or there is an unbalanced force on the motion of the object , , kg=mass , , newton's first and second laws = every change and motion observed/felt is caused by force , , Sir Isaac Newton (1642-1727), British scientist, described relationship between motion and force in 3 laws - Newton's laws of motion , , less friction = the smaller acts over a longer time , , without friction - would never stop "an object at rest remains at rest and an object in motion maintains its velocity unless it experiences a net force" , , objects change their state of motion only when a net force is applied

compound machine = combination of 2+ simple machines ex. chain saw, scissors , , , mechanical advantage = can be ratio between output and input forces. a ratio between output and input distances -machines help do work by changing the size of input force, direction of the force or both *otherwise known as multiplying to force , , 1) actual mechanical advantage (AMA) = friction is taken into consideration AMA= force output (resistance) / force input (effort) *pulley-IMA = # of strands opposing force of load

one = magic number 1) MA > 1 : multiply input force a)less effort required to overcome input force b)greater effort distance to overcome input 2) MA <= 1 : multiply speed (MS) a) greater effort = overcome resistance force b) less effort distance = overcome resistance force 3) MA cannot be less than or equal to zero , , , efficiency = ratio of useful energy output to total energy input, or percentage of work input to work output

astronaut's experience apparent weightlessness -this is due to freefall , , Projectile Motion = there is motion both in the X and the Y direction ex. baseball , , is the curved path followed by an object that is thrown, launched, or otherwise projected , , horizontal component and vertical component, that, when combined, create a curved path *horizontal and vertical components of motion are independent of each other -horizontal pus did not change the vertical motion , , horizontal component/motion = perpendicular or creates a 90 degree angle with Earth's gravitational force , , velocity component is constant after the object is "thrown" (projected, launched, etc) , , vertical component -if there was no vertical component the object would continue in a straight line (Newtons First Law) -gravity gives vertical component - 9.8 m/s ^2

orbits = an object is said to be orbiting when it is traveling in a circular or nearly circular path ex. satellites, moon, planets, other solar systems , , , celestial mechanics : mechanics-motion, celestial-relating to sky/space , , newton + johannes kepler , , objects orbit in elliptic paths -2 focus points : Foci -circles have/focus point , , , objects in orbit around each other share on focus point , , both objects move in elliptical orbits -the orbits have the same shape but different sizes according to their mass ratio , , the center-of-mass occupies one of the Foci -objects are across from each other , across the center of mass , , , Stars of equal mass : Ellipses are of same size , stars can orbit in circular orbits

at the Galactic Center there is believed to be a giant black hole of approximately 4.3 million SM surrounded by red super giants and hypergiants but little dust , , extending from the center is a series of spiral arms with newer stars and significant amounts of dust. Although debated, most sources list 4 spiral arms: the norms and Cygnus arm, Sagittarius, Seutum-Crux, and Perseus , , the galaxy has a diameter of about 100,000 ly and a thickness of 1,000 ly , , our solar system is in a minor arm spur called the Orion Arm (or Oriom Spur) a distance of 27,000 ly from the central bulge , , the spiral arms result from galactic rotation. Our solar system related around Galactic center at a speed of 230 km/s (514,000 mph) resulting in an orbital period of 225 Myr

the milky way is in cluster known as the local group consisting of 54 galaxies. Most are dwarf galaxies that may rotate around the milky way : large/small magellancic clouds (LMC and SMC) , , the next closest galaxy (2.5 million ly) is another spiral called Andromeda. Andromeda has more stars (1 trillion) but when dark matters included, Milky Way is more massive , , astrophysicists predict that Andromeda and Milky Way will collide in 4 billion years (Galactic collisions are common, rarely involve stars) , , the local group is part of a supercluster known as the Virgo Supercluster which may be part of the larger Laniakea Supercluster

*Mirrors can produce different image characteristics based on the shape of the mirror : 1) Plane (flat) Mirror: always give the same image characteristics -virtual/same size/upright ; L/R reversed 2) Spherical Mirror a. concave-images very b. convex- virtual/reduced/upright 3) Parabolic - similar to spherical but not spherical aberration , , Spherical Mirrors : mirror with a curved surface that forms part of a circle (a slice of a sphere) , , spherical mirrors require special terminology to describe them : 1) Center of curvature (c) - the the mirror were drawn as a complete circle, this would be the center 2) Principal Axis - line that runs through the exact center of the mirror through the center of curvature 3) Vertex (A) - the geometric center of the mirror 4) Radius of curvature (R) - the distance from the center of curvature to the mirror along the principal axis 5) Focal Point (F) - the point midway between the vertex and the center of curvature where parallel incident rays to the mirror will be concentrated upon reflection 6) Focal Length (f) - the distance from the vertex to the focal point (1/2 R) NOTE : the above diagram is a concave mirror. A convex mirror will use the same terms, but the arrangement will be a little different (as you will see) , , as said above, there are two types of spherical mirrors : Concave and Convex , , Concave Mirrors: spherical mirror that is silvered on the inside of the sphere (the mirror curves inward) , , the formation of images still follows the law of reflection. It must be determined how to draw the ray diagrams to determine the image characteristic. Through the center of curvature always produces a normal from the mirror surface

the easiest three rays to draw to find the image characteristics are: 1) Radial Ray- along radius- reflects back on itself and goes through C 2) Parallel Ray - parallel to the principal axis (optical axis) - reflects back through F 3) Focal Ray - through F- reflects parallel to principal axis , , , image characteristics : 1) real (object and image on same side of mirror 2) inverted (upside down from object) 3) magnified (image bigger than object) , , , color : visible light can come as the individual colors of the spectrum, or it can be a combination of colors , , the light the eyes perceive is based on the type of light and the reflection of that light from an object , , different light sources emit light of different colors or combination of colors : white light is simply the addition of all colors , , the combination of light is different from the combination of reflected color. Incident light is additive, while reflected light is subtracted , , two colors that Cohen added produce white light are called complementary colors , , Color TV, computed monitors, and color photography all operate on the additive principle of light

Law of Universal Gravitation = all objects in the universe attract each other through the force of gravity , , newton started the equation of universal gravitation , , F=force of universal gravitation , , d=distance between objects *proportional relationships between force and mass , , as mass increases, for one or both objects, the gravitational force also increases *inverse relationship between distance and gravitational force , , , double the distance, the force is cut by 1/4th , , "the greater the distance between two objects, the weaker the force" -this practice is a law , , hypothesis = reasonable guessed based on what you know or observe, true until proven otherwise , , theory = consists of one or more hypothesis that have been supported through repeated testing , , must never be shown wrong, if so theory is disproven , , , scientific laws = short/sweet/always true/direct . Often expressed in a single statement. Generally rely on a math equation. , , *Newtons are the units for force* , , free fall = objects fall at the same rate in vacuum , they fall at a rate of g=9.8 m/s^2 , Fw=m*g , , , Terminal Velocity = air resistance and weight are equal , objects stop accelerating , in some cases objects reach maximum speed , object is still moving down or changing their total displacement over time , , , force of weight = force of air resistance , , Fw= F air

the force on an object due to gravity is called weight , , on Earth , weight is the amount of gravitational force exerted on you because of Earth , , free-fall acceleration near a massive object is constant , , near Earth's surface, force-fall acceleration g=9.8m/s^2 , , F=ma (Newton's second law) , calculates body weight , , weight is equal to mass times free-fall acceleration Fw=mg , , weight=Newtons , , weight is different from mass = they are directly proportional, not the same , , mass=measure of matter in an object , , weight changes with location, mass is always that same , , weight influences shape , , more mass = more support , , *all objects in universe attract each other through force of gravity , , grav force = decreases as distance increases , , all matter is affected by gravity - big masses are easier to notice , the size of the masses and the distance between masses , , grav force increases as mass increases, decreases with distance -when calculating use the distance between the objects centers , , grav force is weakest force because G is constant small number , , freefall=motion of body when only force of gravity is acting on the body , , , in the absence of air resistance, all objects falling near Earth's surface accelerates at the same rate regardless of their mass

one way to increase the strength of the magnetic field is to coil the wire into many loops instead of a straight wore . the RHR in this case means the fingers curl in the direction of current through wire and the thumb points in the direction of the magnetic field , , a device using a coil of wire to generate a magnetic field is called a solenoid. A soilnoid produces a magnetic field very similar to a bar magnet , , sometimes an iron core is placed in the center of the coil of wire to increase the strength of B. This is called an electromagnet , , A galvanometer also works on this principle. A current moving through a coil of wire interacts with a fixed magnet to produce a force. This force can be measured to figure out the amount of current (ammeter) or voltage (voltmeter) present , , jumps circuit = voltmeter , , in circuit ammeter , , the most important application of electricity producing a magnetic force is the electric motor , , the motor has electric current into a wire that is free to rotate around a fixed set of magnets. The current through the wire creates a magnetic field that interacts with the field of the fixed magnets to produce a force. The force causes the coil of wire to spin, converting the electrical energy into mechanical energy

the main components of an electric motor are : 1) brushes = keep electrical contact between source voltage + commutator 2) commutator = split ring that connects the brushes to the rotating coil. The split causes the direction of the magnetic field to switch each half turn so coil continues to spin in the same direction 3) Rotating Coil (armature) = coil of wire connected to the commutator through which current flows to produce a magnetic field 4) Fixed Magnets (stator) = creates a constant magnetic field for the coil to interact with to produce the driving force , , a mechanical output is attached to the coil

inertia is related to an objects mass - inertia is the tendency of an object at rest to remain at rest, or if moving, to continue at constant velocity - all objects resist changes in motion so they all have inertia , , small mass= accelerated by small force, more mass - more force needed , , mass is a measure of inertia , , small mass = less inertia , large mass = more inertia , , matter resists any change in motion "the unbalanced force acting on an object equals the objects mass times it's acceleration" , , when the net force is not zero, Newton's 2nd law applies - describes the effect of an unbalanced force on the motion of an object , , net force is equal to mass times acceleration. The unbalanced force on an object determines how much an object speeds up/slows down , , , newtons 2nd law : net force = mass X acceleration , , F=ma , , for equal forces , a larger mass accelerates less , , used to derive the SI units of force, Newton (N) , one N is the force that gives a mass of one kilogram an acceleration of 1 meter per second squared , , acceleration depends on force and mass , , "acceleration of an object is directly proportional to the net force on the object and inversely proportional to the objects mass"

the net force of an object is equal to the mass multiplied by acceleration ; it is the unbalanced force that determines how much an objects speeds up or slows down , , acceleration is dependent on force and mass , , if mass is held constant, acceleration is directly proportional to force -if acceleration is doubled = force is doubled , , if we hold the net force constant than mass and acceleration are inversely proportional , , v=constant - object is in motion , acceleration is 0 (not always) , , , Fw=m*g - force of weight equals mass times gravity mass : Kg , , Fw=N , , , mass 0 measures amount of matter , , weight = gravitational force an object experiences because of mass , , an objects weight influences shape , , larger animals need stronger skeleton systems to support weight

there are many problems (congenital, infectious, injury, etc) associated with the ear that can cause temporary or permanent hearing loss. These can occur in any part of the ear , , , musical instruments : musical instruments come in three varieties: string/wind/percussion , , , String instruments = stringed instruments create transverse standing waves to produce sound , , because the sound produced by a string does not disturb the air enough to produce significant intensity (loudness), an amplification system is usually used. These are called sounding boards (piano) or sounding boxes (violin, guitar) , , the sound produced can be varied by changing the harmonics (overtones) of the standing wave. This is generally done by changing the length of the string (thickness of the strings also is used) , , Wind Instruments = wind instruments differ from strings in that the air vibrating longitudinally in a column is what actually produces the sound , , to create the air flow in the column a disruption in the original air flow is required (reed, mouthpiece) , , again standing waves are produced at different harmonics by changing the length of the tube (holes, valves, slides) - diameter also has an effect, but minor compared to length , , Percussion Instruments = do not have the same harmonic characteristics of the other instruments , , pitch is the prime component of the percussion instrument and varies with the type of instrument (snare drum, xylophone, timpani) , , the sound is produced by striking another object that vibrates at a certain frequency , , waves and harmonics are produced by tension and shape

the three main components of music are : Sensory= 1) loudness 2) pitch 3) quality , Physical Attribute= Intensity , Frequency , Waveform (harmonics) , , quality (timbre/tone/color) is dependent on the number of harmonics and amplitudes that produce the complex waveform (a Fourier combination of superimposed frequencies and overflows) , , the way that an instrument is played affects the quality (plucking a violin as opposed to using a bow) , , Wave/Particle Duality of Matter : New theories and experiments in the 20th century started showing discrepancies in the existing wave theory to describe light , , they found that light has particle qualities and that matter has wave qualities , , prior to these new theories reflection , refraction, diffraction , interference and polarization of light were all explained by wave theory , , the idea of the photon and subsequent experiments with blackbody radiation, the photoelectric effect, and Compton scattering all required light to be treated as a particle , , now scientists agree that light (or any energy or matter) can either display properties of a wave or a particle. The critical determinant is how light is observed. Thus one of the corner stones of the new quantum mechanics was observation

using units in physics = reasons to use units : 1) give relative magnitude (2 meters or 2 miles) 2) identify quantities in problems (2 meters = distance) 3) unit analysis in solving equations 4) communicates standard and agreed upon information

unit systems : the two most common unit systems are the English unit system (still widely used) and the Metric or SI units (SI= international system of units from the French 'Le Systime International d'Unites"

the normal force (Fn) - the reactionary force of a surfacing pushing back against an objects weight , , "normal" - perpendicular to surfaces in contact , , force of friction = static - occurs between surfaces that are not in motion, it resists the initiation of motion - greater of the two forces! , , kinetic - occurs between moving objects in contact - lesser of the two forces! , , the force of friction in general opposes motion , , rolling friction = when rounded objects are in motion relative to that surfaces , , fluid friction = force that resists the movements of a solid object through a fluid = liquid or gas ex. person skydiving , , friction = due to electromagnetic fundamental force , , calculating force of friction = depends on surfaces on contact (The Coefficient to Friction) , , depends on normal force (Fn)

units : distance (d) = meters (m) , time (t) = speed (s) , velocity (v) , acceleration (a) , force (F) = Newtons (N) , Mass (m) = kilograms (Kg) , coefficient of friction (M) = unitless! , , accel can be negative when you're slowing down , , constant = not changing , , constant velocity = zero acceleration , , graphing = distance vs time , , *time always goes on your x-axis* , , a velocity vs time graph measures acceleration

vectors and scalars = scalar - any quantity that can be fully expressed by a number and a unit only ex. distance, speed, time, mass, temperature -the size of a scalar quantity is called it's magnitude, a scalar has magnitude only

vector - any quantity that requires a direction in addition to a number and unit to be full expressed EX: displacement, velocity, acceleration -a vector quantity has both magnitude and direction -vectors must be properly labeled in either writing by drawing them

cosmology = the study of the origins of the universe , , nebular theory = clouds of interstellar dust from the big band begin to spin and accelerate under the influence of gravity until a large dominant mass begins to form a star 1) Nebula - large accumulation of mostly hydrogen (75%) and helium (25%) and other trace elements 2) Protostar = mass from nebula contracts gravitationally and starts spinning. An early form of fusion fuels the energy to create a hot dense core , , nebula to protostar : 100 million years , , smaller protostars never achieve main sequence and remain a brown dwarf 3) Main Sequence : the primary phase of a star. Protium fusion occurs and the outward flow of energy stabilizes the gravitational collapse , , Protostar to main sequence : 1 million years , , for our sun this happened approximately 4.6 billion years ago (and will continue for the next 5 billion) , , for stars smaller and cooler than sun (Red Dwarf) main sequence may last 100 billion years

white dwarf = when a red giant runs out of fuel it'll begin to contract again. This contraction will trigger a final phase of fusion that will stabilize as a white dwarf , , Hertzsprung- Russell Diagram , , Ejnar Hertzsprung a Danish scientist, used new data using star spectroscopy to arrange and classify stars in 1910 , , in 1913, Henry Russell, an American astronomer, independently added additional information to the diagram which is now famously referred to as the collaborative Hertzsprung Russell Diagram , , this diagram exists in many forms with different identifying characteristics of stars on different axes , , one axis is based on what is called the absolute magnitude of the stars