Principles of Motion and Energy (Physical Science)

Factors that affect strength of electric force

1) amount of charge of each object. The greater the charge, the greater the electric force. 2) distance between the charges. The closer the charges are the greater the electric force.

Convection

It is dependent on contact between molecules, and travel further. Warmer molecules generally move away from the heat source and are replaced by cooler molecules which are then heated up. Circular heat flow (heat current) occurs. Ex: tea kettle water heat source is at the bottom so bottom water warms up first. That warm water expands and rises, then replaced by cool water which also heats up. It is also how we lose heat in our bodies, if our body is warmer then surrounding air then heat is transferred to cold air.

Optics

When observing an object through refracted light we are seeing an image of reproduced copy of the object. Real images have rays that converge at some location, like our eyes or film. They can projected onto screens because light rays from an object are actually traveling to the screen. But virtual images don't have light rays that converge, our eyes simply construct an image. Ex: when looking in the mirror, the light rays that makeup our reflection aren't actually converging to form an image of us.

Inclined Planes

a flat surface that is slanted (ramp). Like, a wheelchair ramp. As you push an object up a ramp, gravity pulls it down. Ramps make it easier to lift heavy objects. A long inclined plane gives mechanical advantage by using less force to move an object. The ratio of the length of the sloped surface to the height it spans. Other examples: waterpark slides, hills, slides, staircases, moving trucks w/built in ramps, etc.

Light

a form of energy made of photons, that enables us to see all things around us. The main source of light on the Earth is the Sun. Light travels at different speeds through different objects. Materials like air, water, clear glass are "transparent" almost all light passes directly through them. Frosted glass, or plastics are "translucent" that allow some light travel through them. It changes direction many times & is scattered when passed through. Objects on the other side of translucent objects appear fuzzy and unclear. Opaque objects (wood, stone, cardboard, metals) block light from traveling through them. Most of the light is reflected by an object or absorbed and converted into thermal energy.

Kinetic Energy

energy due to motion, then converts back to potential energy. Kinetic energy is directly proportional to mass; the heavier an object is the more energy it has. Also, the higher an object's velocity is moving, the greater energy it possesses. It takes more work to move an object w/more mass to accelerate from a state of rest, than a lighter object. Thus, will have more energy. This only happens when both moving objects have same velocity.

Radiant Energy

energy from the sun, or energy of electromagnetic waves. Vibrating particles of the sun create waves that travel through space & time (electromagnetic waves). The sun contains a lot of radiant energy that produces electromagnetic waves. When these waves come in contact w/matter, it causes molecules to move faster and feel warmer. Example: microwaves.

Sound Energy

it is a longitudinal wave (also pressure wave) that travels through a medium of air. Sound waves are spread outward and cause air to be expanded (low pressure) or compressed (high pressure) in the compartment of where the sound waves are traveling to. The differences in pressure cause diaphragms to move back-and-forth, then vibrate air particles around that solid matter, as a result causes atoms/molecules in the air to vibrate also. Pitch can be high or low, and it corresponds to the frequency of the wave.

Electromagnetic Waves/Spectrum

it is an energy wave that transmits energy and produced by charged particles, have electric field and magnetic field where these waves propagate to the right. They travel straight through vacuum (space), not a medium. The electric field is perpendicular to magnetic field and vice versa; both fields are perpendicular to the electromagnetic wave is traveling. It travels the speed of light/nanometers. The vector of magnetic fields point up/down, electric fields are inward/outward. They can have any wavelength and frequency. Higher frequency means smaller wavelengths. The visible spectrum range colors red to violet. Higher frequencies than violet are called "ultraviolet." Objects that appear in color are due to EM waves interact with object's molecules and some wavelengths in the visible spectrum are reflected and other wavelengths are absorbed.

Period

it is the time between wave crests and measured in time units and represented as "T".

Green Leaves

leaf looks green because electromagnetic waves interact w/their chlorophyll molecules waves between 492 & 577 nanometers in length and are reflected. Our eye interprets this as the leaf being green.

multiple pulley

less strength is used to accomplish the same lifting height. The workload does not change, however. The load moves 1/3 the distance that the rope is pulled.

Technologies and instrumentation (digitized signals)

light waves, radio waves, microwaves, infrared waves are digitized signals (sent as wave pulses-1's or 0's) and are more reliable to convey information. They have on and off digitized signals. Information can be recorded, stored for future recovery, and transmitted over long distances. It is better than analog signals because noise is not a problem, have higher quality, carries more information, easily interpreted by other computers.

Magnetism

magnetic field have both positive and negative area, called north/south poles. Same poles repel each other and opposite poles attract. It is carried between objects by photons. The size of the magnet affects the strength of magnetic force, so the larger the magnet the bigger the magnetic force. Also, the distance between the magnets so the smaller the distance, the bigger the magnetic force.

Wheels & Axles

make work easier by cutting down friction, the wheels change the amount of force needed to move the object. People can use carts and wagons to carry their loads. Today, we use wheels on trucks, cars, & buses. Waterwheels are also used.

Electric Current

total amount of charge passing through a metallic wire over a period of time. The flow of negatively charged electrons in one direction is equivalent to the flow of positively charged protons in the opposite direction (conventional current).

Heat

total kinetic energy of molecular motion in a substance. It is energy that transfers between objects when they are at different temperatures. The amount of thermal energy that is added to or removed from a system. Heat is defined in calories (joules), amount of energy to increase temperature. Object's mass and how well it stores heat will exactly say how much temperature it changes. The more mass an object has, the more heat it takes to change its temperature since massive objects have more matter, and takes more energy to change its average kinetic energy. Also, the higher the object can store heat, the more energy transfer it takes to change temperature. Heat flows through conduction, convection, and radiation.

Waves

transfer energy as they travel. It is a disturbance propagating through space. It occurs when one particle affects the particle next to it. Wave's energy is proportional to its amplitude squared, for instance double the amplitude = 4 times the wave. Waves work when they move objects. We can see this work when it moves generator parts for electricity, water waves when disturbing the surface, sound waves cause levitation. Waves are reflected, absorbed, and transmitted through various materials.

Infrared waves

wavelength is a little longer than what our eyes can detect and are warm objects, such as our human body, thermal light, etc. It is mostly invisible to the human eye, some warm objects can emit light such as fire; but can be felt through heat, and we encounter everyday. The wavelength varies from nanometers to micro meters. Infrared waves also serve us to see objects in the universe that are invisible to telescopes. They pass through dense gas and dust, with lower scattering and absorption. Ex: night-vision cameras, remote controls to send signals to televisions and other AV equipment.

Specular Reflection

when all light rays reflect off a surface at the same angle. The more shiny and mirrored a surface, the more specular reflection occurs.

Predicting a future motion

when an object's past motion exhibits a regular pattern, future motion can be predicted. Newton's second law of motion is supported to predict future motion.

Wave Reflection

when light bounces off a material. Reflection of a wave is a process by which a wave (light, sound, radio, etc.) hits the object and bounces off it. An incident ray (wave is moving toward the surface) of light strikes a mirror and touches the point of incidence. Then another line, called normal (perpendicular) line goes through the point of incidence. The angle between incident ray & normal is called angle of incidence. So when incident ray strikes in the mirror at any degree angle, it will bounce off that same degree angle. The ray that bounces off is called reflective ray. The angle between reflective & normal lines, is called angle of reflection. The incident angle = the reflected angle.

Diffuse Reflection

when light waves hit different imperfections on surfaces and bounce off at different reflected angles. The more dull a surface, the more diffusion reflection occurs.

double pulley

when there are two pulley devices. The load moves half the distance that the rope is pulled. There is more force required.

Collisions

when two objects bump into each other where they exert forces on each other for a short period of time. Also, energy is transferred from one object colliding to the second object, affecting how the second object moves and change direction.

Law of momentum conservation

when two objects collide in a closed system, the total momentum of the two objects before collision is the same as the total momentum of the two objects after collision. The momentum of each object may change, but total momentum remains the same.

Mechanical Advantage

when you get more force out of a machine than you put into it. output force/input force = mechanical advantage.

Wind Energy (renewable source)

wind in natural environment is capable doing big jobs; it is used to make electricity, like fossil fuels or nuclear power. It harvests energy from the wind and converts it into electrical power. For instance, wind turbines use wind blows to move the blades. Wind made electricity in the outlet to charge phones, computers, etc. Drawbacks would be that it messes up the view of landscape, large blades kill birds and noise pollution.

Gravitation

• natural phenomenon by which objects w/mass attract one another. • the force of attraction between all masses in the universe. Especially the attraction of the earth's mass for bodies near its surface. • Responsible for keeping the earth and the other planets in their orbits around the sun, for keeping the moon in its orbit around the earth, for the formation of tides, etc.

Incandescent light bulb

also known as electric lamps, and are source of electric light. An electric current (electricity) passes through a thin filament, heating it until it produces light. The enclosing glass bulb prevents the oxygen in the air from reaching the hot filament, which would be destroyed rapidly by oxidation.

Issac Newton's First Law of Motion

An object will continue to remain at rest (ex. rock resting on the ground) or uniform motion (ball bouncing in the air), unless acted upon external unbalanced force (ex. human pushing the rock or goal gate captures ball). Also, the ball will stay in a constant velocity in the absence of an unbalanced force.

Technologies and instrumentation (Analog signal)

Analog signal is a continuous wave and vary in signal strength (amplitude) or frequency (time). Examples are human voice, clocks with moving minute/hour hands, telephones with chords, not wireless.

Radiation

Doesn't depend on the movement of molecules and heat is transferred through electromagnetic waves. The bigger the object's area, the faster it will radiate heat. It is also proportional to temperature. Ex: Warm coffee emits radiation to its area. Radiation can cause loss of heat. If walls, floor, ceiling, of a room are colder than you, then you radiate more heat to the room, than the room radiate heat to you.

Electric/Magnetic fields

Electric field is a measurable effect generated by any charged object. The electric field created by a charged object, is the electric force between objects. The fields exist between objects exerting forces on each other even though objects are not in contact.

How wind makes electricity

Energy companies use large windmills, called wind turbines, 200-300 ft tall. Then the companies build large wind farms with lots of wind turbines. When the wind blows, it turns large turbines. The kinetic energy produced in the turbines turns a shaft inside. The shaft is connected to many gears that causes smaller shafts to turn faster. The smaller shafts drives the electrical generator and generates electricity by spinning a coil of wire around a magnet inside an electromagnetic generator. The movement of the wire around the magnet causes electricity to flow through the wire. The electricity can then be transported to our homes through large towers. Once it gets to our homes, we can plug in our phones and computers.

Coulomb's Law

describes how protons in an atomic nucleus that are positively charged, keep negatively charged electrons from wondering off which are photons.

Electromagnetism

draws oppositely charged particles together (protons/electrons) after absorbing each other's light. Also causes atoms to stick together and create molecules that form us and everything around us. Without electromagnetism matter would dissolve.

Wave absorption

Occurs when photons from incident light hits atoms and molecules from a medium and causes them to vibrate. Every material can be broken down into individual atoms/molecules. It's these atoms and molecules vibrating that absorbs some of the energy away from the wave and less of the energy is being reflected. This vibration then releases the transferred energy in the form of heat. Ex: black pavement absorbing energy from light. Black pavement becomes hot from absorbing the light waves and little of the light is reflected making the pavement appear black. A white pavement on the other hand, reflects more and absorbs less so white pavement will be less hot. The more an object's molecules move and vibrate the hotter it becomes. Photons bounce around during this absorption process and lose bits of energy to numerous molecules along the way. This radiation forms a longer wavelength infrared energy.

radio waves

Radio waves vary from centimeters to length of cars, ships, mountains, to longer than the diameter of planet Earth. Commonly used in communications and entertainment, and send signals from one place to another. Radio waves are at the red end of the electromagnetic spectrum, which have the lowest energy, lowest frequency, and longest wavelength. Due to its long wavelength, they can be bounced off the Earth's ionosphere, allowing radio stations to transmit their broadcasts over long distances, without being in line-of-sight of all their listeners. Also, the antennas are good telephoto lens happening in the moon. Many astronomical discoveries have happened due to radio waves. The sun also bursts radio waves. Planets also emit radio waves. Ex: radio stations, and wireless networking, antennas etc.

Electric force

The force of attraction or repulsion of carried positive and negative charged particles, respectively protons/electrons, due to an electric field. Electric force is greater than gravity. Unlike charges attract, like charges repel.

Law of conservation of energy

energy can be neither created nor destroyed, but can be transferred from one object to another; or change from one form to another. Generally takes 3 ways for energy to transfer: movement of objects, movement of waves, & movement of heat.

Motion

a change in position of an object over time. It is described in terms of displacement, distance, velocity, acceleration, time and speed.

Friction

Whenever two objects are in contact their surfaces rub together creating friction force. The harder things are rubbing together, the more friction there is. For instance, it is friction that causes humans to stay on the ground. Friction is everywhere and causes work to heat up.

Electricity

a stream of electrons trying to get from a negative charged source to a positive charged substance.

Pulley (or a block)

a wheel w/a groove around its edges, and has a rope or cord threaded through the groove. Pulleys change direction of a force, transmit rotational motion, or realize a mechanical advantage in linear or rotational system of motion. It helps an individual lift an object by spreading the weight of the object over the length of the rope. Instead of pulling up to lift an object, you need to pull down. There is no mechanical advantage of using a single pulley. More rope needed to spread work out. Ex: sailboats, cranes, catapults, flag poles, etc. In the human body, the kneecap which alters the direction in which patellar tendon pulls on the tibia.

Electromagnetism - Electrostatic

acts on objects that have electric charge, and electrostatics are either positive or negative. Atoms typically have same number of protons and electrons. However, some substances take on electrons easily (ex: rubber) while others give up electrons (ex: wool sweater). When substances with opposite tendencies come in contact, the electron from the atoms of one object jump into the atoms of another object.

Magnetism (electric currents)

also generates magnetic field, demonstrating an intimate connection between electricity & magnetism. Light is also part of electromagnetic radiation. Faster motion of magnet, electric current induces more.

Light Energy

also known as electromagnetic energy, is the only energy we can see directly It is formed through chemical, radiation, and mechanical means. Ex: radio signal, visible light, infrared waves, x-rays, ultraviolet, the Sun, Moon, stars, fire, neon lights, light bulbs, etc. Light is a particle and a wave, electric and magnetic fields are producing waves. Light energy is tied to wavelength, shorter wavelength has more energy than longer wavelength. Light energy is typically absorbed by molecules to produce a reaction from one object to another.

Gravity

an attractive force felt by all forms of matter. It is a force that makes everything fall down towards the Earth. It is the force of two objects pulling on each other. Ex: humans, otherwise we would fly off into space. Issac Newton first discovered the mathematics of gravity, then Albert Einstein made improvements.

Effects of a balanced/unbalanced force on an object

an unbalanced force on an object will change its direction/speed (ex: a force on a side of a ball causes it to roll one direction). A balanced force on an object will cause it to stay at rest due to multiple forces or balanced forces acting upon the object. The forces are at equilibrium because gravity, and other balanced force(s) on the same object have a net force of zero, and thus the object will remain at rest unless acted by an external force (ex: person rolling the ball).

Simple Machines

basic mechanical devises with very few parts that help us move objects by applying force and doing work. They make our work easier because you use less force to move an object. There six types of basic simple machines: the wheel & axle, the lever, the pulley, inclined plane, the wedge, & the screw. In order to do this work, you may have to work against gravity & friction. work = force x distance.

Second Class Lever

both effort & load move in the same direction. The load is between the fulcrum & the effort. When you lift, your load lifts also. Multiply force but do not change the direction of the input force. Ex: wheelbarrows, baby strollers, bottle openers. When humans engage in a push up it acts like second class lever. The feet is the fulcrum, body weight is the resistance, effort is applied by the hands.

Third Class Lever

both effort and the load move in the same direction. The effort is between the fulcrum & the load. Ex: baseball bat, fishing pole, shovel, tennis racket, etc. When you swing a baseball bat, the fulcrum is your handle of bat, the effort is your hand pushing it forward to swing. The load is the ball. Our forearm is a third class lever, because a longer forearm can create faster motion of the hand.

Photons

carry electrostatic force between the electron and proton. They are the same particles that carry light and heat which is why electromagnetic force is able to travel at the speed of light. Photons are created by protons/electrons.

Thermal Energy

energy possessed by an object or system that has an internal temperature, due to movement of particles within the object or system. It has the ability to do work, same as kinetic energy. The hotter the substance, the more its molecules vibrate. Example: putting a pot of water on heated stove. The stove contains thermal energy. The more you turn up the stove, the more internal energy the stove contains. The thermal energy in the stove causes heat of the pot and water. The heat in turn, speeds up the particles w/in the pot & water.

Nuclear Energy

energy released from fission & fusion. Nuclear reaction changes the nucleus of an atom. Scientists use nuclear energy to provide clean power for us. Example: Nuclear fission is used to generate electricity in our nuclear power plants. The fission releases a lot of energy and other neutrons as well. Those neutrons cause a chain reaction and cause other uranium nuclei to split & additional energy is released. The heat of this fission causes steam. However, it produces radioactive waste that is harmful to life & the environment. Fission is used in atomic bombs & radiation, also. Nuclear fusion comes from the light & warmth of the Sun. It has a clean and safer energy source than fission.

Electrical Energy

energy stored in charged particles w/in an electric field. This is another type of potential energy. The charged particle (that is positive and negative) will have the potential to move or do work, due to the force of the electric field. It can be used to move charged particles through a wire (current) from a power plant to our homes and businesses. This is also known as electricity. Examples: lightning, or lamp as light energy and thermal energy (heat).

Chemical Energy

energy stored in the bonds of atoms & molecules that hold chemicals together, same as potential energy. It is released through chemical reaction, often producing heat. Once chemical energy is released from a substance, that substance is transformed into an entirely new substance. Example: dry wood is a store of chemical energy, as it burns in fire place chemical energy is released & converts to thermal energy (heat) and light energy. Wood is turned into ashes.

Magnetic Energy

energy within magnetic field that results in metals repelling or attracting each other. This is related to electrical energy.

Refraction

explains why objects appear bent as light coming from a fast medium passes through a slow medium, and vice versa. When ray moves from the air to a transparent medium like glass, (angle of incidence - theta 1), the ray's angle passing into the glass (angle of refraction - theta 2) will be less than the incident angle. The object appears bent because the rays coming from the object into our eyes don't travel in a straight path. It is bent so that the bottom of the object appears to be in place where its not. Glass has a higher refractive index than air. When ray enters a medium w/an increased index of refraction the angle of refraction decreases, and vice versa. The higher the index of refraction, the lower the angle of refraction. (Remember car analogy!)

Issac Newton's Third Law of Motion

for every action, there is equal and opposite reaction. Ex: when we sit on a chair, our body exerts a downward force on the chair and the chair also exerts force on the body. Without the force, chair would collapse and we wouldn't be able to sit. For birds, wings exert a downward force on the air and the air exerts equal upward force to the bird which helps to fly in the air.

Frequency

frequency of the wave is the number of times per second the wave cycles; it is measured by Hertz or cycles per second and often presented as "f".

What happens when thermal energy is added/removed to gas?

gas particles expand when heated, and contract when cooled. Refer to Boyle's Gas Law and Charles Law. As temperature increases, volume increases.

Speed of Propagation

how fast the disturbance the wave is coming. The speed of mechanical waves depends on the medium that the wave is traveling through.

First Class Lever

is between load & effort. The effort pushes down for the load to go up. It can multiply force or distance depending on the location of the fulcrum. Ex: seesaw, scissors, pliers. For the human body, nodding our heads employs first class lever with the spinal chord as the fulcrum.

Velocity

is the rate of change of position w/time and focuses on direction of object. The basic formula is v = s/t; v is velocity, s is displacement, and t is time. Displacement is the distance traveled during the time.

Temperature

measure of the average kinetic energy of molecular motion in substance.

Amplitude

measure of the displacement of the wave above and below its resting position (peak/trough). It is generally calculated by looking at graphs and measuring the height of the waves. It measures strength and intensity of the wave. The amplitude of a transverse pulse is related to the energy which that pulse transports through the medium.

Acceleration

measurement of change in an object's velocity. The formula for this is: A = v/t or A = (change of velocity)/(change in time).

Momentum

measurement of mass in motion. Any object moving has momentum. In physics, momentum of an object is equal to the mass x velocity.

Speed

measures how quickly an object moves from one place to another. To calculate, speed = d/t.

Work

movement of an object by some force or effort applied.

Electric Currents

movement of electrons through electrical conductor, typically in copper wire. It contains same number of protons/electrons, but electrons are more looser. Electrons will flow to the positive charge of the battery, while electrons coming from the negative charge side of battery will flow in the wire to make up the difference. There is a clockwise motion. Voltage is potential energy, pushing electrons on top battery so electrons convert to kinetic energy to flow. When it flows through a circuit, energy is transferred from the power supply to components in a circuit.

Microwaves

next closest to the red end spectrum, are used to heat our food because of their high enough energy to increase the motion of the molecules in our food without ionizing the atoms (allowing electrons to escape). Doppler radars also use microwaves for weather forecasting, Also cellphones, TV signals, are part of the microwaves. They vary from centimeters down to one millimeter. Microwaves are grouped into bands and send different information to scientists. For instance, C-band microwave penetrate through clouds, dust, smoke, snow, rain to reveal Earth's surface. L-bands, are used for forest mapping, by measuring surface soil moisture and identify areas of deforestation, and also used for GPS in our phones/car.

Thermal Equilibrium

no heat transfer between objects.

Ultraviolet

not visible to the human eye, headed towards the blue side of the spectrum, and is bad for us because it has higher energetic light, due to photons having more energy; and shorter wavelength. Its energy is high enough to ionize atoms and break molecular bonds and damage DNA molecules. This energy can be added to your cells and break them apart and cause damage. For this reason, UV causes sunburns and skin cancer. Ex: tanning beds, sunning, etc. Higher frequency are x-rays, even more dangerous. Gamma rays are even a higher frequency, photons are more energetic than ever. Gamma rays come from space or nuclear reaction and is the most dangerous.

Displacement (distance)

object's overall change in position from starting point to the final point. To calculate, draw a vector from your starting point to your final position and measure the length, s = vt.

Screws

one long inclined plane wrapped around a center post. Screws hold objects together. They help to apply more force to an object and also converts forces. The direction depends on which way you turn the screw. The distance between the threads is called a pitch. A screw can convert a rotational force (torque) to a linear force and vice versa. The ratio of threading determines the mechanical advantage of the machine. More threading increases mechanical advantage. When screws rotate outward, the weight rises & when turned inward the weight lowers.

light waves

one part of the electromagnetic spectrum, where it is visible to our eyes. Light moves a wave, bouncing and reflecting off objects so we might see them. When light from the sun hits an object, several things can happen: reflection and refraction. Ex: radio waves, microwaves, infrared waves, visible light, ultraviolet,

Fluorescent lamp

or fluorescent tube, is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce shortwave ultraviolet light that causes a phosphor to fluoresce, producing visible light.

Lever

they are a straight rigid rod or board that moves on a fixed point called a fulcrum. The load is the object you need to lift, the effort is the force you use on the lever. Levers make work easier by using leverage which multiplies force. You can change mechanical advantage by moving position of the fulcrum. In the human body, the fulcrum is the joint axis, bones are the levers, skeletal muscles create the motion, and the weight of the body is the resistance.

Conduction

or thermal conduction, depends on physical contact between molecules and is a spontaneous transfer of thermal energy through matter, due to collisions between atoms & molecules transfer kinetic energy from higher temperature to lower temperature. The higher thermal conductivity of a material, the faster heat would be transferred. Also, the greater temperature difference, the faster heat flows. Ex: cup of coffee stirred w/a metal spoon. The spoon will quickly get hot. The molecules in the hot coffee make the atoms in the spoon vibrate quickly. To minimize thermal energy transfer, can be external measures such as closing windows, and plugging drafts. By radiation would be to reflect as much as the radiation as possible. Ex: coolers, thermos, etc. because they are silvered inside. Also insulation reduces heat transfer.

Transmitted Wave

passes through matter; like sound coming through a wall from the room next to you.

Chemical Energy (Ex #2)

plants use solar energy to make sugar from carbon dioxide & water. Sugar, carbon dioxide, and water are held together by chemical bonds. Energy is needed to hold them together, and solar energy provides plants to put the carbon, hydrogen, and the oxygen atoms together in the form of sugar. This energy transformation is solar energy to chemical energy, that holds sugars together.

Force

push or pull of an object. A force can cause an object to accelerate, slow down, remain in place, or change shape. It is measured by mass x acceleration.

Solar Energy (renewable source)

radiant light and heat from the Sun. Ex: solar heating, solar panels, solar water, wind power, water evaporation, or using sun to dry clothes, heat food, or plants using solar energy to produce sugars, etc. We can use Passive heating to keep houses warm. Solar power can be used for electricity like solar panels, which are made of solar cells. These cells are silicons, connected by four strong bonds that keep electrons in place and no current flows. When photons, from the sun, hit the top of solar N-silicon cell, electrons will be attracted to the surface of the cell and creates voltage between the two cells, N-silicon cell and P-silicon cell that has extra spaces for electrons. This creates a positive charge on one side and negative charge on the other side. When an electric circuit is formed across between the two layered cells, current will flow, powering electrical equipment. Drawbacks: amount of sunshine in a specific place changes due to time of day, the weather, and time of year. Another is that current technology takes up a lot of solar cells to produce a decent amount of electricity.

Issac Newton's Second Law of Motion

rate of change of momentum of an object is directly proportional to the unbalanced force in the direction of force. Ex: human pushing a huge rock causes it to move slightly, but stronger force like horse, causes rock to move a greater distance. Mass is greater on stronger force, therefore are able to apply greater force on object, whereas mass is less on lesser force which results in applying fewer force on object.

frequencies of light

red has the longest wavelength and violet has the shortest.

Gravitational Potential Energy

referred as 'height energy' because the higher up an object is placed the more GPE it has. Ex: using muscles to lift the ball off ground, until it is above your head then drop it (kinetic energy). Ball bounces back up quickly. Energy has been conserved. After ball hits the ground, the Earth absorbs it in 2 ways: heat the dissipates in the ground and movements of earth itself.

Wedge

shaped like an inclined plane, however it is an object that moves. Wedges are used to break things apart or hold them together. It makes works easier by converting force from one direction to another. A force pushes the wedge straight into an object. The wedge then converts that forward force into two sideways forces, which push objects apart. Friction helps a wedge hold objects together (i.e. doorstop). Other examples that break things apart: knives, axes, other cutting tools, plows, our teeth, pencil sharpeners, etc.

Newton's Law of Gravitation

states that all objects in the universe are attracted to each other through the force of gravity. The amount of gravity affecting the object depends on 2 things: the masses on the objects being attracted and distance between the objects. The gravitational force between objects increases as the masses of those objects increases.

Potential Energy

stored energy due to position, then converts to kinetic energy. There are 3 types: elastic potential is energy stored as a result of deformation of an elastic object (rubber band); gravitational potential is energy stored based on distance from the ground (book on top of a shelf); chemical potential energy stored inside battery.

objects change in motion depends on

sum of the forces on the object and mass of the object. For instance, when a truck hits a small car, the forces are equal but small car experiences greater velocity (motion) than the truck. An investigation experiment could be cars rolling on a ramp, 3 forces are acting upon it: ramp pushing up to support the car, the car's mass, and friction.

What happens when thermal energy is added/removed to liquid?

temperature increases, molecules & atoms vibrate and expand. Liquids contract when cooled.

What happens when thermal energy is added/removed to solid?

temperature increases, molecules & atoms vibrate faster and move apart. Mass of the object remains the same. Solids contract when they lose heat, like melting or any way to reduce its size. When solids expand or contract, they have change in length and volume. The bigger the object, the more it will expand or contract. Ex: expansion joints in bridges expand in summer weather, and contract back in cooler weather.

Energy

the ability to do work, to move objects and can take several forms.

Wavelength

the distance between two corresponding points on back to back cycles of a wave. It answers, "how far did the initial pulse of a wave go after one cycle?" or "one period?" It is a distance from one resting point to another resting point and is measured between two crests of a wave or two troughs of wave and is represented as (λ).

Weight

the force of gravity on an object.

Electromagnetic Energy

the way energy travels in wavelengths in electric and magnetic fields. Ex: gamma rays, x-rays, ultraviolet radiation, etc.

Time

time of distance traveled, t = d/s.