BYU Physical Science Final/Exemption Exam

Practice:What are the forces, velocities, and acceleration upon you as you ride an elevator?

(Before you move the forces are balanced) 1. Gravity 2. Contact force (As the elevator accelerates you have to overcome gravity, so the contact force has to overcome gravity) 3. As you move between forces you are in uniform motion again. (As you stop Gravity must overcome contact force)

Forces in Fluids

(Fluids: anything that flows) 1. Bounded: Lakes tubs, tubes etc. 2. Pressure: bounded: equalizes to all points. unbounded: depends on depth ONLY 3. Buoyant Force: Weight of Displaced water (determined by the object's volume). BF is always UP because the greater pressure comes from the lower depth. Buoyant force is affected ONLY by the VOLUME of the object. Depth and Weight do not mater. Whether an object will float or sink depends on the net force.

The Photoelectric Sxperiment

(The Dual Nature of Light) 1. Shine a flashlight on electrons: nothing happens 2. Shine a brighter light on the electrons: nothing happens 3. Shine an UV light: electrons jumped off -proof that light acts like a particle -the particles carry their energy in frequency: characteristic of particles -the particles carry their energy in their amplitude: characteristic of waevs

silicates:

1) ashetsots: breaks off in strings 2) mica: breaks off in plates 3) quartz: breaks in chunks

heat transfer

1) conduction- touching something hot and having it burn you 2) convection- using some type of medium to transfer energy to something else (furnace and vents) 3) radiation- heat traveling by itself

4 fundamental forces

1) strong nuclear force: acts on protons and neutrons on nucleus of an atom 2) weak nuclear force: not important for this class 3) electromagentic interaction: positives and negatives, daily life. From atoms to continents.

Special theory of relativity

1) the laws of nature are the same for all observers in inertial frames of reference (ie principles of motion symmetry) 2) the speed of light in a vaccuum has a constant value of approximatley 300,000 km/sec regardless of the speed of the device emitting the light or the speed of the observer observing the light [\\.

Wave Properties

1. Amplitude 2. Wavelength 3. Frequency 4. Speed: how fast a wave is moving (frequency times wavelength). Speed is constant, it does not change for a particular wave in a particular motion.

4 Ways to Gain Knowledge

1. Authority: someone from a position of power 2. Intuition: hunch 3. Sensory Data: using 5 sense 4. Reason: using previous experience to find assumptions to establish a set of context to come to a truth

Practice: What are the forces on a car passenger as it turns a corner at a constant speed?

1. Centripetal force: you are accelerating because this force makes you change direction. 2. Gravity 3. Contact Force

Energy Transformations: A jumping frog: How does it happen?

1. Chemical potential energy (ingested food) 2. Elastic Potential energy (muscles) 3. Kinetic energy (the jump upwards) 4. Gravitational potential energy 5. Kinetic energy (coming down) 6. Thermal energy (dissipated through ground)

Types of Waves

1. Compression Longitudinal (solids, liquids, and gas) 2. Transverse Shear (Solids Only) 3. Surface Waves (Along the surface of liquid) 4. Standing Waves: When a wave combines back on itself by reflecting or wrapping around

Heat Transfer

1. Conduction 2. Convection 3. Radiation

Types of Conservation

1. Conservation of mass 2. Energy 3. Mass number 4. Charge 5. Linear Motion 6. Conservation of mass and energy are only conserved together at a night speed. Otherwise consider mass and energy to be conserved separate.

Models of Matter

1. Continuous: What you see is what you get NO EXCEPTIONS (if you cut a piece of butter, you can do that continuously forever) 2. Molecular: every thing is made up of little molecules, different matters made of different types of molecules, always in motion, obey fundamental laws (gravity, motion) explains temperature, 3. Plum Pudding: postive and negative charges 4. Rutherford 5. The Bohr Model 6. Quantum Model

6 Self Evident Truths

1. Existence: there is something that exists 2. Time Symmetry: results will be same no matter WHEN you did it (gravity was here millions of uears ago) 3. Position Symmetry: no matter where you perform a experiment, the results will be the same 4. Occam's Razor: if you have competing theories about something, the simplest explanation is the one you should use (gravity) 5. Non-contradition: two opposing viewpoints, one HAS to be wrong 6. Causality: one thing causes something else

The Electromagnetic Spectrum

1. Gamma Rays (high frequency, low amplitude) 2. X-rays 3. Ultraviolet 4. Visible light (we can see) 5. Inferred 6. Microwaves 7. Radio waves (low frequency, high amplitude) based on wavelength/ frequency Rabbits mate in very unusual xray gardens Continuous spectrum = rainbow Discrete Spectrum= only a few colors

Practice: You are in a rotating cylinder wearing roller skates. What are the forces upon you?

1. Gravity 2. Contact force: you are pushing on the floor and the floor is pushing back on you.

The Dual Nature of Light

1. Is light a wave? YES 2. Is light a Particle? YES

Practice: You have two charged balls that are one meter apart. How does the force on either ball change if you bring them closer together so that they are now 0.5m apart.

1. It gets stronger 2. You do not need to know the change on the balls for electrical force. It is ALWAYS strongest when they are closer together no matter if the force is repulsive or attractive. 3. Fe=KQq/d^2

Mass of two falling balls

1. Mass has nothing to do when an object hits the ground, only depends on how close the object is to the earth. 2. Bigger mass= greater force of gravity 3. Balls will hit the ground at the same time

What can you say about an object's weight and mass as it moves farther from the earth?

1. Mass stays the same/Constant 2. Weight decreases: if you are further away from the earth the object's gravity has less pull on you.

Practice: You have two charged objects one meter apart. How does their potential energy change if you decrease the separation by half to 0.5m?

1. NOT enough information. Are the charges the same or different? 2. The electrical force depends on distance: lower the distance the greater the force. 3. Potential energy DEPENDS on the charges: repulsive: potential energy will be greater when they are farther apart. attractive: potential energy will be greater when they are closer together.

Wave Phenomena

1. Reflection: bouncing off 2. Refraction: bending/ change in medium 3. Interference: two waves in the same place at the same time (constructive if peak meets at peak or trough meets at trough. Destructive if peak meets at trough or vice versa). Diffraction and interference are the two things that ONLY WAVES do

Fatty Acids

1. Saturated: straight, chain easily stacked, non-polar, heard to break up, worse for you 2. Unsaturated: somewhere a hydrogen is missing within the chain, forms kinks, lower melting point, better for you 3. Trans-fat: use to be unsaturated, but man-made and stretched out. WORST for you, has kinks, stack easy and clog arteries, linear and lots of surface area

(5 Predictions) Objects moving at a high speed as observed from a "stationary" frame of reference are measured to be...

1. Short (length contraction) 2. Fat (mass increase) ... e=mc2 3. Slow (time dilation) 4. Simultaneity 5. Conservation of mass and energy together

Doppler Shift

1. Wave frequency and wavelength change when the wave emitter or receiver is moving. 2. When something is moving IN FRONT of it the wavelengths will be shorter BEHIND it the wavelengths will be stretched out.

Kinetic Energy

1/2MVsquared at same temperature, something with a smaler mass will move faster than something with large mass (helium vs argon) heat flows from hot to cold Balloon is just air molecules colliding with plastic Gases are less dense because they move more

Three things that mean disorder is increasing (order will NEVER increase)

2nd Law of Thermodynamics Entropy: Law of Increasing Disorder

Plum Pudding (Tomsen) Model of Matter

3. Plum Pudding (Thomsen Model) -Molecules can be broken into parts of positive and negative charged fragments -HE THOUGHT: One giant positively charged chunk and lots of little negatively charged pieces

Circular motion is...

Acceleration or a single force pulling inward.

Radioactive Decay

Alpha: dispels a He nucleus (2 protons, 2 neutrons), numbers change Beta: Turn a neutron into a proton and dispel an electron, change numbers

Molecular Model of Matter

Brownian Motion: Matter is made of different molecules in constant, random motion. -Temperature is average Kinetic energy of particles -Particles move faster and expand when they are hotter

Speed of light

C= 3e^8 m/2 Speed of light is CONSTANT which makes it: 1) short 2) fat (mass will increase) 3) slow (clock will tick slower)

Solidd Liquid Gases

Can hold its own shape, doesnt need container fixed volume, changes shape based on container Variable volumes, variable shapes

Mass Spectrometry

Can't separate one molecule from the others, so take TONS of molecules, put them through molecule breaking machine and measure mass of all different parts of molecule. Intensity: y axis Mass: x axis Look for the parent peek, which is LARGEST mass (represents entire molecule) Find atomic mass of each atom (number on bottom of little box on periodic table)

Energy gravtiational potential energy Kinetic energy elastic potential energy NEC Thermal

Capacity for something to change/do work capacity for something to fall (things higher up have more gravitational potential energy) capacity to move (faster=more capacity) having something be able to move back to what it was before Nuclear (within the nucleons of atom), electric (movement of electrons), and chemical (energy contained within bonds) Constant movement of atoms (thermal heat)

Change in distance will effect...

Change in distance will effect a change in force and vice versa

Activation Energy

Charts with funny curve, represent chemical reactions. Energy released will be represented in form of light or heat. Exothermic: releases energy, end lines up below middle line Endothermic: releases no energy, end lines up above middle line Activation Energy: how much energy it takes to start the reaction (work you put in) -if it takes a long time then activation energy bump will be little Catalyst: decreases amount of energy needed to get the same reaction Energy Favorable: when you get as much or more energy out than you put in

Longitutinal wave/ compression wave vs sheer/transverse wave

Compression is always forward in direction, not disturbed vs moves forward always, but moves up and down (ONLY TRAVEL THROUGH SOLIDS)

Rocks are held together by...

Electromagnetic interactions

Covalent Bonds

Electrons are SHARED Polar Molecules (F,O,N,CL,S) -Uneven distribution of electrons (ONLY covalent) -dipole dipole (strongest form is hydrogen bonding) Nonpolar -dispersion forces (weak) Formed between TWO NON-METALS Localized electrons Widely spaced orbitals ONLY bond that forms molecules properties: 1) non conductive 2) transparent 3) low MP and BP (highest for H bonding, second is polar, third is nonpolar)

Ionic Bonds

Electrons are TRANSFERRED permenently Very brittle Don't respond from Network Solids Non-conductive (except when dissplved or melted) High melting points and boiling points Attraction between ions are EXTREMELY strong Formed between METALS AND NON-METALS Localized electrons Widely spaced orbitals. metals on left side, nonmetals on right side 4 properties of ionic bonding: 1) brittle 2) transparent 3) high melting and boiling point (highest) 4) ionic conductors (not good conductors if solid)

Measure of force equation

Fe= KeQq/d2 Fe= force of electromagentivity Ke= constant Qq= two different charges D= distance

Gravitational Force Equation

Fg= Gm1m2/d2 Fg= froce of gravity G= Gravitational pull m=mass d=distance

Newton's Third Law of Motion:

For every action there is an equal and opposite reaction. Example: stepping off a boat onto the bank of a lake, as you move towards bank, the boat moves away from the bank. -the idea of force pairs

Ionization energy

From bottom left to top right, higher the ionization energy, higher to the right on the table energy required to strip atom of its valence electrons

atomic volume

From right top to left bottom, the smaller the atomic volume, the lower and further left it will be on the periodic table

Fusion and Fision

Graph: Average Nuclean Mass: y axis Atomic number: x axis Small atomic number: nucleons bigger Fusion is LEFT side of graph Fission is RIGHT side of graph Reactants will always have a higher mass than the products Always go from higher to lower

Galaxies are held together by...

Gravity

Rutherford

His experiment 1. Sent alpha particles (positively charged) through a golf foil 2. Most were expected to pass right through 3. A few bounced straight back! 4. Previous model could not account for something incredibly dense and positive in the center 5. The positively charged particles were repelled by something positive in the foil -Dense, positive nucleus -Electrons orbiting around the outside -Most of atom is empty space (doesn't explain discrete spectra: electrons aren't giving off light, if they are just flying around they would give off light) basically discovered that positive charges are in nucleus

Newton's First Law:

I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. Essectially Galileo's concept of inertia ("Law of Inertia") Example: If something is in motion it will stay in motion unless there is an outside force to act upon it Inertia: comes from the idea of mass

Practice: You are sitting in a chair. What is the reaction force to gravity pulling on you that is required by Newton's 3rd Law?

If the earth is pulling on you you must be pulling back on the Earth.

Bonds

Ionic Covalent Metallic

Linear momentum Angular momentum

L= MV A=MVR This is also part of law of conservation Linear momentum at high speeds, not the same, nothing can go faster than the speed of light, still conserved but not in the same way Moemtnum is conserved, has to be transferred

micro vs macro kinetic energy

Micro= heat macro= normal kinetic energy ex: fridge, to make it cold in fridge it pulls heat out of fridge and puts cold inside... to do so it needs to make extra heat,

When does the gravity really go to zero?

NEVER

Forces vs. Net Force

Net Force: the sum of all forces acting on an object. An object can have multiple forces acting on it but there is only one net force. Net force and acceleration are ALWAYS in the same direction

Inter-molecular forces (outside of molecule)

Only applies to Covalent bonds 3 kinds: 1. Hydrogen bonding: strongest! Holds together things that involve H+O,N,F Di-pole Di-pole: next strongest, holds together polar molecules with anything other than what Hydrogen Bonding holds together 3. Dispersion forces: very weak, vander walls

Pressure Equation

P= F/A Pressure Force Area

Electronegativity

Periodic table: increases UP and to the RIGHT

Uniformatarianism

Present is key to the past Anything that happened today most likely has happened in the past

Balancing Equations

Products on left, reactants on right Diatomic molecules: i. SEVEN SHAPE!!! ii. I (I) iii. Br (Bring) iv. Cl (Clay) v. F (For) vi. O (Our) vii. N (New) viii. H (House) ix. You will NEVER see these atoms alone, they must be with another one!! x. You may see a question that says which equation is balanced and correct...you MUST make sure the diatomic molecules are not alone!

fatty acids

Saturated fats: no kinks, bad, melting temp high as they get bigger Unsaturated fats: kinky, melting temperature lower as they get bigger Trans fats: unsaturated, no kinks

Quantum Model

Since light is a wave and a particle; maybe matter is too! (basically discovered that everything is a wave and particle, smalller= easier to see as waves) Double slit experiment: 1. Electrons are in orbit 2. Orbitals are standing waves of probability 3. Are arranged according to the exclusion principle 4. Let's draw an energy well! (Some People Dance Funny) a. S (You can fit 1 orbitals) I cloud b. P (You can fit 3 orbitals) Jump Rope c. D (You can fit 5 orbitals) Double Jump Rope d. F (You can fit 7 orbitals) Jump Rope with two doughnuts in between e. Each orbital can only hold 2 electrons 5. Atomic volume: diameter of nucleus and all electrons around it. As we add shells diameter (atomic volume) gets bigger. As you go from left to right, add electrons, so shells suck closer to the nucleus and atomic volume gets smaller. 6. Ionization of energy: energy required to remove the outer most electron. Harder to remove=ionization energy higher (Hard=high). If easy to remove=ionization energy lower (Easy=low). Ionization Energy Required goes opposite of the Atomic Volume

The Bohr Model

The "fix" to the solar system model: electrons are in specific, non-radiating orbits (like a target) 1. Energy of a photon is a function of its frequency 2. Explains discrete spectra -A photon jumps up and absorbs energy (lots of colors and bars of black) -Then it falls back down and gives off light (lots of black and bars of color) -Color of light is measured by the frequency it had to lose to get back down -If it goes from REALLY high to REALLY low it had to give off energy/high frequency light Problem: electrons are still orbiting, that can't happen

Newton's Second Law of Motion:

The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector. Acceleration is caused by unbalanced forces, no unbalanced forces, no acceleration. It is how fast or how slow speed is increasing.

Types of Net Force

The sum of all forces acting upon an object 1. Balanced force: no net force (uniform motion) 2. Unbalanced forces: net force (accelerated motion) 3. No net force: no acceleration

Newton's Second Law (connections)

This is the most powerful of Newton's three Laws, because it allows quantitative calculations of dynamics: how do velocities change when forces are applied. Notice the fundamental difference between Newton's 2nd Law and the dynamics of Aristotle: according to Newton, a force causes only a change in velocity (an acceleration); it does not maintain the velocity as Aristotle held. *This is sometimes summarized by saying that under Newton, F = ma.

Metallic Bonds

Two metals come together, network solid, have one valence electron form conduction bands (stacking of orbitals), bottom is valence band top is conduction band, Electrons are delocalized (network solid) meaning they can move betweeen bands Malleable Ductile Conductive Reflective Opaque High melting and boiling points Over-lapping orbitals Semi-conductors, higher the temperature, worse they are at conducting (opposite with semi-metals) Formed between TWO METALS Semi-metals: elements on the staircase, have a band gap, need a certain amount of energy, how LED lights work, electrons go back down in energy and give off a photon

Velocity vs. Acceleration and their equations

Velocity: speed (faster slower) and direction (centripetal acceleration: orbits, turning cars etc.) Acceleration: a change in velocity Velocity: postition 2- postition 1/ time Acceleration: velocity 2- velocity 1/ time Unifrom Acceleration: constant acceleration per second

Wavelength equation

Wavelength= speed/frequency better with small things opens the door for quantum physics

Is light a wave?

Yes and no, duality, theory of max plank that light is not a wave Einstien: wave particle duality, photons have wave particle duality If you break down light into photons, it will still interfere with itself

radioactive decay

alpha: eject He nucleus, atomic number decreases by 2, total mass decreases by 4 beta: neutron turns to proton, atomic number increases by 1, total mass stays the same gamma: releases energy, atomic number and mass stay same

Ionic conductor

conducts electricity when melted or dissolved (salt)

Standing Wave

creates a stable patterns

earrth

crust (outmost, very light), mantle (things bonded to oxygen), core (iron) mechanical layers 1) lithosphere: crust, very rigid and solid antheno 2) athenosphere: plastic and silly putty (techtonic) 3) mesosphere: completely solid 4) outer core: liquid 5) inner core: completely solid see via observation, mass and density, meteorites, seismology (s waves and p waves)

Buoyancy/ Archimedes Principle

displaced fluid: the weight of water/liquid displaced by the object Buoyancy: strictly the weight of the upward force ex: cannonball vs balloon, cannonball has more buoyant force because it is larger. But its gravity also has a more buoyant force, so it overcomes the buoyant force that it has Bf> Gf= float Bf< Gf= sink Buoyancy has to do with its VOLUME!

energy reaction diagrams

energy in bonds= y axis time/extent= x axis activation energy: how much I need to start reaction after reaction, energy goes lower than intial starting energy.... excess energy (is conserved) and comes out as heat, light (this is an exothermic reaction) these are ENERGETICALLY FAVORABLE endothermic: finally energy stored in bonds is greater than intial energy... have to take in energy... will feel cold upon touch

reversibility/ irriversability

entropy states that things can't go back to the way before (an egg doesnt go back together) 1 reversible thing: beaker of water at zero degrees celcius goes betweeen ice and liquid water over and over

Columns rows

families groups

Terminal velocity

force of gravity and air resistance are equal to each other -acceleration ceases at that point (with a skydiver, this is when you deploy the parachute, then air resistance is greater than gravity)

Work

force/distance -idea is to know that you can transfer between different types of energies (change from gravitational to kinetic energy)

fusion and fission

fusion= pros: high energy, no waste cons: high activation energy, not energetically favorable, hard to control fisson= breaking of elements, low activation energy, energetically favorable, easy to control cons: low on resources, radioactive waste

Doppler Effect

if the source of a wave is traveling, higher frequency in front of it than behind it

Vibrational Spectrometry

if they match, they are similar molecules

Hezenburgs Principle

if we know about position, we don't know as much about momentum

Speed is measured in

m/s

reactants products equation

mg + F2(reactants)= MgF2 (products)

Noble gases

on the right column of table, wont give up valence electrons have full valance shells, dont want to give one up

Waves:

reflection: hits the surface and bounces off defraction: bends around corners or when its confined it branches out (ocean wave) refraction: when it hits a medium (an environment in which something exists) or changes mediums, it changes speeds interference: one wave can affect another wave (either positively or negatively) Node= at zero Anti-node= interference at its maximum amplitude= measure of interference (from node to crest or node to trough) amplitude is high= frequency is low and ice versa Frequency is osculations (curves) per second, wavelength is physical length of a wave

General theory of relativity

space and time connected -mass pushes down on space time and causes it to curve -kind of like a trampoline with space time (the dip pulls stuff towards you)

Sheer forces: Compression forces: tension

tearing motion (liquid cant) forces going inward/ compressing something going outward gases can support only compression Liquids can support compression or tension

Stronger the force is holding a substance together

the higher the melting point will be

Practice: If a semi and a cooper collide...

they exert the same forces on each other. But the cooper will accelerate backward more because its greater mass (This is an example of Newton's 3rd law)

Quantum model of the atom

think of electrons as waves, not particles, because they cant accelerate -bascially just a cloud of negative matter not orbits, orbitals

As temperature increases...

total energy increases temperature stays constant when changing from a solid to liquid, once that happens, molecules start moving faster again

entropy equation

universe= system + surroundings (everything else) entropy will always increase (if it goes down it a system, it must go more up to compensate)

Copper

very good conductre, electrons move through it easily rubber is not good (don't let electrons run through it= insulators)

To increase the energy in a sound wave... To increase the energy in a photon...

you increase the amplitude you increase the frequency