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The Best Dang Regents Physics Review Sheet Ever, Cheat Sheet of Physics

Ranken Technical CollegePhysics

Very good review cheat sheet for your Physics exam with formulas

Typology: Cheat Sheet

2019/2020

Uploaded on 11/27/2020

ekadant
ekadant 🇺🇸

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268 documents

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The Best Dang Regents Physics Review Sheet Ever!
Math, Graphs, and Vectors:
1. The fundamental SI Regents Physics units spell “MASK”: meters, amperes, seconds and kilograms
All other units are derived. In calculations, leave original units if not sure. ” ” means “final – initial”
2. W = work (energy) or watts. w = weight. m = mass or meters. P = power, but p = momentum.
J = impulse or joules. E = energy or electric field. T = tension or period. Time t must be in seconds!
3. Recognize quantities by units: distance d (in m), speed v (in m/s), acceleration a (in m/s2), mass m (in kg),
force F(in N), etc. Quantities with no units: coefficient of friction and refractive index n
Use equation to determine units. Ex: units for [Work] = [F][d] = [ma][d] = kg·m/s2·m = kgm2/s2 = 1 J
4. Unless the answer is prefixed, get rid of prefixes, eg, the c in cm (except the k in kg) before a calculation.
5. Scalars have magnitude (size) only. Ex: distance, mass, time, speed, coefficient of friction, all energies,
work, power, charge, resistance, potential difference, , T, f, , , refractive index
6. Vectors = scalar (magnitude) + direction. Ex: displacement, velocity, acceleration, all forces, all fields,
momentum, impulse, etc. Vector = arrow. Draw with ruler to scale. Draw the arrow tip!
7. Add vectors A and B using either:
a/ tip-to-tail: Resultant from tail b/ parallelogram:
of A to tip of B Resultant is diagonal.
8. Magnitude of R depends on angle between the two vectors being added. See diagram 1.
At 00: mag. of R = A + B. At 1800: mag. of R = A - B. At 900, mag. of R = √(A2 + B2).
From the sum (max.) to the difference (min.) is the total range of possible resultant magnitudes.
9. Any vector can be resolved (broken down) into an infinite number of paired components.
10. “Show your work” means: equation, substitution with units, answer with units
11. Plot points. If a straight line, use a ruler. Use best-fit line (not data points) to calculate slope.
Find what slope represents by forming ratio: y-quantity/x-quantity, then look in PhysRT.
Ex: Plot a vs. F. What does slope represent? a/F =? See PhysRT, where a/F = mass m
Kinematics (Study of Motion):
12. distance d = position. DVD ~ 10-3 m thick, your finger ~ 10-2 m wide, and DVD ~ 10-1 m wide
displacement d (vector) = distance (scalar) + direction. Distance is the magnitude of the displacement.
13. speed v = the rate of change in distance. Average v = d/t. Speed is the magnitude of the velocity.
velocity v = rate of change in displacement velocity v (a vector) = speed (a scalar) + direction
14. Add v’s as vectors: resultant vplane w.r.t. ground = vplane w.r.t. air + vair w.r.t. ground
15. acceleration a = time rate of change in velocity. a is a vector. a has same direction as v.
16. a/ The slope of the distance-time graph = speed. Greater speed greater slope.
b/ The slope of the velocity-time graph = acceleration. Greater acceleration greater slope.
c/ The area under the velocity-time graph = displacement. Positive area positive d (right or up).
17. Uniform motion = constant velocity a = 0
Pattern: Graphs:
18. Accelerated motion = constantly changing velocity acceleration = constant for Regents Physics
Pattern: Graphs:
19. Word clues: Starts from rest: vi = 0; comes to rest: vf = 0; average vavg = (vi + vf)/2 (not in PhysRT)
Use vavg for v in d = vt. Positive is up or right, negative is down or left.
20. If a and v are same direction, speed is increasing. If a and v are opposite direction, speed is decreasing.
21. Free fall (no air resistance): a = -g = -9.81 m/s2 (independent of mass and speed).
22. For a dropped object: vi = 0, d = -4.9t2 and vf = -9.8t. Falls d = -4.9 m in 1st second (NOT -9.8!)
23. Projectile fired straight up: Remember the symmetry between times and speeds going up and down.
speeds vup = vdown, tup = tdown = ½ ttotal, vtop = 0, BUT atop = -9.81 m/s2. It is still in free fall!
24. Horiz. fired project.: vi is horiz.: vi = vix = const., viy= 0, and vy = -gt. a = ay = -9.8 m/s2. See diagram 4.
Rate of fall is indep. of vi and same as for dropped object. Dropped and fired hit at same time!
Parabolic trajectory. Velocity v tangent to path. Fnet = weight = downwards, so is a. Fx and ax = 0.
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Download The Best Dang Regents Physics Review Sheet Ever and more Cheat Sheet Physics in PDF only on Docsity!

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The Best Dang Regents Physics Review Sheet Ever!

Math, Graphs, and Vectors:

  1. The fundamental SI Regents Physics units spell “MASK”: meters, amperes, seconds and kilograms All other units are derived. In calculations, leave original units if not sure. ” ” means “final – initial”
  2. W = work (energy) or watts. w = weight. m = mass or meters. P = power, but p = momentum. J = impulse or joules. E = energy or electric field. T = tension or period. Time t must be in seconds!
  3. Recognize quantities by units: distance d (in m), speed v (in m/s), acceleration a (in m/s^2 ), mass m (in kg), force F(in N), etc. Quantities with no units: coefficient of friction and refractive index n Use equation to determine units. Ex: units for [Work] = [F][d] = [ma][d] = kg·m/s^2 ·m = kgm^2 /s^2 = 1 J
  4. Unless the answer is prefixed, get rid of prefixes, eg, the c in cm ( except the k in k g) before a calculation.
  5. Scalars have magnitude (size) only. Ex: distance, mass, time, speed, coefficient of friction, all energies, work, power, charge, resistance, potential difference, , T, f, , , refractive index
  6. Vectors = scalar (magnitude) + direction. Ex: displacement, velocity, acceleration, all forces, all fields, momentum, impulse, etc. Vector = arrow. Draw with ruler to scale. Draw the arrow tip!
  7. Add vectors A and B using either: a/ tip-to-tail: Resultant from tail b/ parallelogram: of A to tip of B Resultant is diagonal.
  8. Magnitude of R depends on angle between the two vectors being added. See diagram 1. At 0^0 : mag. of R = A + B. At 180^0 : mag. of R = A - B. At 90^0 , mag. of R = √(A^2 + B^2 ). From the sum (max.) to the difference (min.) is the total range of possible resultant magnitudes.
  9. Any vector can be resolved (broken down) into an infinite number of paired components.
  10. “Show your work” means: equation, substitution with units, answer with units
  11. Plot points. If a straight line, use a ruler. Use best-fit line (not data points) to calculate slope. Find what slope represents by forming ratio: y-quantity/x-quantity, then look in PhysRT. Ex: Plot a vs. F. What does slope represent? a /F =? See PhysRT, where a /F = mass m

Kinematics (Study of Motion):

  1. distance d = position. DVD ~ 10-3^ m thick, your finger ~ 10-2^ m wide, and DVD ~ 10-1^ m wide displacement d (vector) = distance (scalar) + direction. Distance is the magnitude of the displacement.
  2. speed v = the rate of change in distance. Average v = d/t. Speed is the magnitude of the velocity. velocity v = rate of change in displacement  velocity v (a vector) = speed (a scalar) + direction
  3. Add v’s as vectors: resultant vplane w.r.t. ground = vplane w.r.t. air + vair w.r.t. ground
  4. acceleration a = time rate of change in velocity. a is a vector. a has same direction as v.
  5. a/ The slope of the distance-time graph = speed. Greater speed  greater slope. b/ The slope of the velocity-time graph = acceleration. Greater acceleration  greater slope. c/ The area under the velocity-time graph = displacement. Positive area  positive d (right or up).
  6. Uniform motion = constant velocity  a = 0 Pattern: Graphs:
  7. Accelerated motion = constantly changing velocity  acceleration = constant for Regents Physics Pattern: Graphs:
  8. Word clues: Starts from rest: vi = 0; comes to rest: vf = 0; average vavg = (vi + vf)/2 (not in PhysRT) Use vavg for v in d = vt. Positive is up or right, negative is down or left.
  9. If a and v are same direction, speed is increasing. If a and v are opposite direction, speed is decreasing.
  10. Free fall (no air resistance): a = -g = -9.81 m/s^2 (independent of mass and speed).
  11. For a dropped object: vi = 0, d = -4.9t^2 and vf = -9.8t.  Falls d = -4.9 m in 1st^ second (NOT -9.8!)
  12. Projectile fired straight up: Remember the symmetry between times and speeds going up and down. speeds vup = vdown, tup = tdown = ½ ttotal, vtop = 0, BUT a top = -9.81 m/s^2. It is still in free fall!
  13. Horiz. fired project.: vi is horiz.: vi = vix = const. , viy= 0, and vy = -gt. a = a y = -9.8 m/s2.^ See diagram 4. Rate of fall is indep. of vi and same as for dropped object. Dropped and fired hit at same time! Parabolic trajectory. Velocity v tangent to path. Fnet = weight = downwards, so is a. Fx and a x = 0.
  1. Projectile fired at angle with initial speed vi: Symmetry as in straight-up case. See diagram 4. Velocity is tangent to path. Fx and a x = 0. Fnet = Fg = weight downward, so a is also. Still free fall. Horiz. comp.: vix=vicos stays same. Use TOTAL time to find range: dx = vix x ttotal Vert. comp. viy=visin , Use viy as initial speed and solve problem as a ball thrown straight up Speeds vup = vdown, tup = tdown = ½ ttotal, BUT vtop = vix and is ≠ 0. As before, a top = -9.81 m/s^2 Trajectory is parabolic. With air resistance, range and max. height are less and no longer parabolic Max. range if = 45^0. Max. height and max. time if = 90^0. Complementary angles (eg, 20^0 & 70^0 ) have the same range, but higher angles have longer ttotal and reach a higher max. height.

Forces, mass, Newton’s Laws and Gravity:

  1. A force F is a push or pull. Forces are vectors: F = magnitude (strength of force) + direction.
  2. Forces measured in newtons, N (derived). 1 N = 1 kg·m/s^2 = weight of a stick of butter or small apple
  3. Two basic types: a/ contact : normal, tension, friction. b/ at a distance : weight & other field forces
  4. Isolate all forces with a free-body diagram. Draw only forces (no v, p, etc) acting on the object. Resultant force depends on angle between vectors: Add if 0^0 , Subtract if 180^0 , etc, as in #7-8 above. Resolve into x- and y-components with: Fx = Fcos and Fy = Fsin. See diagram 5.
  5. All mass has the property (not a force) inertia = resistance to velocity. More mass  more inertia. Convert masses to kg before any calculations! 1$ bill ~ 10-3^ kg, butter or apple ~ 10-1^ kg, student ~ 50 kg
  6. Newton’s 1st: No net force needed for motion. Otherwise known as the Law of Inertia: “An object at rest tends to stay at rest, and an object in motion tends to stay in motion.” In other words: Net force = 0  object is in equilibrium  a = 0  constant velocity In equilibrium: up and down (y) forces balance, right and left (x) forces balance. See diagram 5. If forces are balanced (Fnet = 0), object may be at rest OR moving with constant velocity.
  7. Equilibrant force (-R) is equal in magnitude but opposite to the resultant vector (R). See diagram 2.
  8. Newton’s 2nd: a = Fnet/m. Rearrange: Fnet = m a. a has same direction as the net F. A net, unbalanced force (object not in equilibrium) MUST produce acceleration. F’s cause a ’s. To find a : Find net F by adding force vectors. Divide by mass (not by the weight!).
  9. Elevator: Accelerating up  FN (what scale shows) increases; accelerating down  FN decreases
  10. Newton’s 3rd: A exerts force F on B. B exerts force – F on A. These equal and opposite forces always are same type, but act on different objects. Forces, NOT the accelerations, must have equal magnitude. Note: If F 1 = your weight of 600 N. Then reaction to F 1 = You pull up on Earth with a 600-N gravity force.
  11. Gravity and Weight: All masses attract each other with a gravitational force Fg (weakest force) Fg = Gm 1 m 2 /r^2 Ex: 2r  ¼ F, 3r 1/9 F, etc, 2m  2F, 3m3F, 2m AND 2r  F/2, etc (inverse square) Stronger as you move closer: (1/2)r  4F, (1/3)r  9F, etc
  12. G = universal gravitational constant is NOT the same as g = the acceleration due to gravity.
  13. Weight (in N) w = mg = Fg = force of Earth’s gravity acting on object. If g ≈ 10 m/s^2 , then w ≈ 10mass.
  14. A gravitational field g exists around every mass. g is radial and inward for a point mass. See diagram 7.
  15. g = Fg/m = strength of gravitational field (in N/kg) = acceleration a due to gravity (in m/s^2 ) = w/m g is proportional to 1/r^2 , so weight = mg is also 1/r^2. Note: 2 RE above surface is tripling the distance! On or near the surface of a planet, g is constant as long as you don’t get too far away. See diagram 7.
  16. Mass m is same everywhere. Weight w changes, b/c g changes: w = mg. Eg, gMoon = (1/6)gEarth

Uniform Circular Motion, Momentum, Impulse, Friction:

  1. Centripetal forces Fc can be provided by a string, road friction, a seat, air, etc. In absence of centripetal force, objects fly off on a tangent to the circle (NOT directly away from the center of the circle).
  2. Centripetal Fc (a net force and ≠ 0) and a c are directed toward the center of the circle. See diagram 8.
  3. Velocity vector is tangent to the circle, but changes direction, so it accelerates alhough speed is constant.
  4. Both a c and Fc are directly prop. to v^2 , and inversely prop. to r. Fc (NOT ac!) is directly prop. to m.
  5. Momentum p = mv is a vector in same dir. as v. Objects can have inertia (mass), but no p if v = 0.
  6. Changes in p: p = mvf – mvi = m(vf – vi) = m v. Elastic (hit & bounce) collisions  greater p
  7. Impulse J = Fnett = p  same units: 1 N·s = 1 kg·m/s (but ≠ newton). J is a vector w/same dir. as Fnet In plot of F vs. t, area = J. Impulse Fnett = p  Maximize p by increasing F or t (follow through)

3 A 2 A

1 or 5 A

  1. Charge is conserved. The sum of charges before = the sum of charges after. Always.

(before) q 1 + q 2 + … = q 1 ' + q 2 ' + … (after) Signs matter!

  1. One’s objects loss in charge = other object’s gain. Ways to charge objects ( see diagram 11 ): a/ Friction: rub two insulators  charges are directly moved from one object to other b/ Contact: Two metals touch  excess charge is spread out over both metals b/c charges repel In metals: e-'s can move, so excess e-'s repel and spread themselves out on outside surface. Ex: If 2 identical metal spheres touch, divide TOTAL charge by 2 to find q on each. c/ Induction: Bring “+” object near neutral conductor, ground opposite side, conductor becomes “-“
  2. Coulomb’s Law: Every two q’s exert an electric force Fe on each other: Fe = kq 1 q 2 /r^2 (inverse square) Ex: 2r  ¼ F, 3r 1/9 F, etc, 2q  2F, 3q3F, 2q and 2r  F/2, etc As you move charges closer, F increases: (1/2)r  4F, (1/3)r  9F, etc
  3. An electric field E = Fe/q exists around every charge q. See diagram 10. Units: [E] = [Fe]/[q] = N/C.
  4. E is a vector with direction given by the direction of the electric force Fe on positive test charge q.
  5. E = 0 inside a conductor, even if there is charge q on conductor. Safe in a metal car hit by lightning.
  6. E field lines: Lines of electric F; closer lines  stronger E; lines don’t cross; Fe is tangent to lines
  7. E field of 1 charge is radial and 1/r^2. Lines are out of a positive q, but into a negative q E fields of 2 charges is similar to the B field around two magnets. See diagram 10.
  8. E field of 2 parallel plates: constant, equally spaced lines except near edges, out of + and into – plate Fe on q between plates has same mag. and dir. everywhere because Fe = qE, and E is constant. Proton between plates feels same mag. Fe as electron, but opposite dir. Proton a is less b/c more m.
  9. Potential difference V = W (work or energy)/q = energy needed to move a charge q in a E field. Units are volts, V. If W in J, then q in C. If W in eV, then q in e. 1 V = 1 J/C = 1 eV/e An electronvolt eV is a tiny energy (NOT a voltage) unit. To convert: 1 eV = 1.60 x 10-19^ J.

Current and Circuits:

  1. Current I is the rate of charge q passing a point. Need a complete circuit and potential difference. Conservation of charge at a node (junction): Iin =Iout.
  2. I = q/t Charge q in coulombs, C, I is in amperes, A. If q is given in electrons, convert to C first.
  3. Potential difference (voltage) sources: batteries (DC), generators (AC), etc, all supply energy
  4. Electrons e-^ move most easily. Conventional I is positive and moves from high to low potential.
  5. Electron collisions make drift velocity slow compared to actual e-^ speed between collisions.
  6. Conductors (metals, ionized gases, etc) have e-^ free to move. Insulators: e-^ and free and hard to remove.
  7. Resistivity values given in PhysRT are used to calculate R for metals. Smaller  smaller R. Units: Ohm·meters: ·m. In the equation with , area A = r^2 with r in meters for wires.
  8. R = L/A  Short, thick, cold silver wires make the best conductors.
  9. Ohm's Law: Resistance R = V/I = slope of V (y-axis) vs. I graph. Units: ohms 1 = 1 V/A If graph of V vs. I is straight  ohmic. True for most metals at constant temperatures.
  10. For given voltage: If no R  short circuit (danger). Higher R  less I. If R = ∞, I = 0  open circuit.
  11. Voltage represents energy used to push electrons around. Assume no voltage loss along circuit wires. Voltage is “across” two points, but current is the charge passing “through” circuit element.
  12. Series circuits: More resistors  more total R  less I  less power P. (see PhysRT V divides up in direct proportion to the R of each part. for equations) I is the same in all parts of circuit, UNLESS you change the circuit!!!! See diagram 12. Disconnecting one part of series circuit makes I = 0 in the entire circuit.
  13. Parallel circuits: More resistors  LESS total R  more I  more P  faster power drain (see PhysRT Current divides up in inverse proportion to the R of each part. for equations) V is the same across all branches of the circuit. See diagram 12. If one parallel element is disconnected, rest of circuit is NOT affected.
  14. Series resistors: Req = sum = bigger than biggest R. For n equal series resistors R: Req = nR Parallel resistors: Req = smaller than smallest R. For n equal parallel resistors R: Req = R/n
  15. Voltmeters are hooked up across (in parallel). Ammeters are hooked up in series. See diagram 12.
  16. Electrical energy W and power P: Add W or P for each part of circuit, regardless of series or parallel.

Magnetism and Electromagnetism (E&M):

  1. Magnetism is caused by current I. A magnetic field B exists around every I (any moving q).
  2. Direction of a magnetic field (B) = the direction that the N pole of a compass points.
  3. B field lines point from the N pole to the S pole outside the magnet and from S to N inside the magnet.
  4. In iron, nickel and cobalt, magnet domains are lined up. This can be randomized by raising temperature.
  5. B field of bar magnet: Lines out of N, into S pole. Denser lines  stronger field. Lines don’t cross. B force is tangent to the B field lines. Strongest near poles. Every N has a S pole (no monopoles).
  6. Like poles repel, opposite poles attract. Know the B Field of two bar magnets. See diagram 13.
  7. Earth’s B field is like a bar magnet, drifts and flips occasionally, and is a S pole near geographic North.
  8. Solenoid (coil) B is like a bar magnet and stronger with more I or more wire turns or adding an Fe core.
  9. Electromagnetic induction: Relative motion v betw. conductor and B field induces voltage in conductor. Either conductor or magnet can move. Max. voltage V if angle between v and B is 90^0 , minimum if 0^0.
  10. Motors and generators both use the force that a B field exerts on moving charges: same hardware. motors: electrical energy to mechanical generators: mechanical energy to electrical.

Vibrations and Waves:

  1. Period T = time to complete one cycle = time for a wave to travel one wavelength.
  2. Frequency f = number of vibrations or waves per second. 1 Hertz hz = 1/s = s-1^ = 1 cycle per second.
  3. T = 1/f  T is the inverse of f and vice versa. Period T must be in seconds.
  4. Amplitude A = displacement from equilibrium (half of peak-to-peak value). See diagram 14.
  5. Simple (small A) pendulum: T increases (and f dec.) with length, independent of bob mass and A
  6. Resonance occurs when an object is forced to vibrate at its natural frequency. The result is an increase in the A (NOT the f!) of vibration. Ex: bridges, wine glasses, air in tubes, strings, swings, etc
  7. Vibrations cause pulses and waves. A pulse = single disturbance of medium. Repeated pulse = wave. A wave is a periodic disturbance of a medium that transports energy, but NOT mass.
  8. medium (pl. media) is what a pulse or wave propagates through: vacuum, gases, water, solids, liquids, etc
  9. wavelength = distance d between successive identical points on a wave = d that wave travels in 1 T
  10. phase: how much a wave is shifted relative to reference point or another wave phase angles: 1 = 360^0 , ¾ = 270^0 , ½ = 180^0 , ¼ = 90^0
  11. Longitudinal: wave v and medium v are parallel. Transverse: wave v perpendicular to medium v
  12. For transverse waves: Leading edge points move up, trailing edge points move down. See diagram 14.
  13. Wave v depends on properties of medium (for example temperature, density, etc), not on amplitude Wave speed v = d/t or v= f. Units: m/s = Hz·m.
  14. If v remains constant, increasing f decreases and vice versa.
  15. Interference: Two or more waves in same medium at same time. Interference is a wave property. Superposition: Add 2 or more waves algebraically to get a resultant wave. See diagram 15.
  16. Constructive interference  Resultant amplitude is greater. Sounds louder or appears brighter. Waves are in phase. Phase difference = 0, 1 , 2 , … or 0^0 , 360^0 , 720^0 , …
  17. Destructive interference  Resultant amplitude is less. Sounds quieter or appears dimmer. Waves are out of phase. Phase difference = ½ , (3/2) , (5/2) , … or 180^0 , 540^0 , 900^0 , … Total destructive interference: Waves have equal amplitudes and are completely out of phase. Resultant is zero. Sound (noise) or light cancels out completely.
  18. Standing waves: interference of two waves with same A, speed and f, but opposite directions. Nodes = no movement, destructive interference. Antinodes = constructive interference. See diagram 16.
  19. Diffraction = bending of wave behind an obstacle or opening. Diffraction inc. as inc. or as size d of opening or obstacle dec. Diffraction is a wave property. Same and v behind obstacle. See diagram 19.
  20. Double-slit experiment combines diffraction and interference from 2 waves. See diagram 15.
  21. Doppler effect: Change in observed f of wave due to relative motion between source S and observer O If S and O are approaching: higher f (higher pitch or bluer light) and shorter Same v for both. If S and O are receding: lower f (lower pitch or redder light) and longer Same v for both. The source f remains constant! The faster the relative motion, the more the f. See diagram 17. If relative motion is at constant v, f remains constant. If motion accelerated, f will change.

m

E

F 1

F 2

R

- R = equilibrant

Fnet = w

ax= ay =

  • g

fired with a certain vi

fired with a speed 2vi

slope = c^2

900

R =diagonal

1800

R = difference = minimum

vtop ≠ 0

00

R = sum = maximum

w

wperp = wcos

wll = wsin

  1. Energy can be converted to mass and vice versa: Use E = mc^2 (mass is kg) OR 1u = 931 MeV. More mass means more energy. Slope of E vs. m equals c^2. c^2 is simply a conversion factor, and does not imply motion.
  2. 1 universal mass unit u = (1/12) mass of C-12 nucleus. Masses can be given in u or in kilograms.
  3. In fission or fusion, “missing mass” is converted into energy (E = mc^2 )

reactant 1 + reactant 2 + ….  product 1 + product 2 + … + ENERGY Add up reactants, add up products, then subtract  represents energy released (aka “mass defect”)

  1. Matter-antimatter annihilation: mass + antimass  2 photons. Each photon Eph = (mass)c^2 Pair production: 1 photon  mass + antimass. The photon Eph must be at least = 2(mass)c^2
  2. Total mass-energy is conserved, but mass and energy by themselves are NOT, b/c m   E
  3. Only charged particles can be accelerated in a particle accelerator. Energy gained is W = qV.
  4. Only integer multiples of e = 1.60 x 10-19^ C can be found on any particle. (Except quarks.)
  5. Quarks: charge = (+2/3)e or (-1/3)e, with opposite charges for antiquarks.
  6. Matter m with charge q has antimatter with same mass m but opposite charge – q. See diagram 24.
  7. All matter is either a/ a lepton or b/ a hadron. Hadrons are either: a/ mesons (qq) or b/ baryons (qqq). Quarks are never found alone. That is why it is ok that they have charge that is a fraction of e. Add up charge on all quarks in particle to find total charge on particle, which must be an integer.
  8. The antiparticle of a meson qq is qq. The antiparticle of a baryon qqq is qqq. Same m, but opposite q.
  9. Protons (uud) and neutrons (udd) are made of up and down quarks because those two quark flavors are the most common and the least massive flavors. More massive quarks are formed at higher energies.
  10. The 4 Fundamental Forces (excluding dark energy):
  11. Strong nuclear (strongest) always attractive and very short range  holds the nucleus together Protons are attracted to other protons (and to neutrons) if close enough by this force!
  12. Electromagnetic  between q’s  attractive OR repulsive, 1/r^2 , and infinite range
  13. Weak nuclear  important during radioactive decay (don’t need to know for Regents Physics)
  14. Gravity (weakest) always attractive, 1/r^2 , and infinite range. Important b/c planets are neutral.

Diagrams:

  1. R depends on direction between vectors: **2. Equilibrant: 3. Inclined plane:
  2. Projectile Motion:** In both cases: parabolic trajectories and F and a are down!

dropped ball

CW

v

F, a

v

v

F, a

F, a

F, a (^) CCW

F, a

v

v

F, a (^) F, a v

v

F, a

ET = PE + KE = constant Loss of KE  gain of PE Loss of PE  gain of KE

PE KE

E^ ET

b/ by induction:

positive charge:

negatively charged object:

a/ by contact:

neutral conductor Touching^ –^ equal q on each. (If 1 sphere bigger  more q)

separate

neutral conductor: charges separate ground

Remove ground, then remove the charged object. Note: charges now opposite original charged object.

charged object

charged conductor

g ~ 1/r^2 for a point mass: Earth w

Fg (weight) or g as a function of distance from Earth:

1Re 2Re

1Re 2Re 3Re 4Re

3Re 4 Re

5Refrom center

w 4

w 9

w 16

w 25

from surface

9. Conservation of Energy for a freely falling object or a pendulum with no friction: 5. Forces:

Fx = Fcos

Fy = Fsin

F

d F W = Fd

6. Work:

Fnet = 0 a = 0 at rest OR const. v

d

W = Fxd = Fcos d

F

Fnet ≠ 0 a to right vel. can be pos. or neg.

F

w = FN w = T

slightly curved at edges

FN

d

F W = 0 d^ b/c^ = 90^0

F W = Fd

At rest:

g = 9.81 m/s^2 is constant at Earth’s surface:

7. Gravitational **fields g:

  1. Uniform circular motion:
  2. Electric fields:
  3. Charging** (all diagrams could have all charge signs reversed):

string

FN =

w + F

Before:

e-^ at rest

photon at v = c

e-^ now has KE

Eph is less, so longer, but v still = c

around an obstacle:

around a corner:

Bigger or smaller d:  More diffraction

22. Refraction of Light:

wavefronts:

incident waves with v 1 , f 1 , A 1 (reflected wave not shown)

transmitted waves with v 2 , f 2 , A 2

faster

slower

smaller n

bigger n

If rays 1 and 2 are parallel, then n 1 = n 2 (same v)

slowest

1

2

1

2

fastest

fastest

slowest

same same

fastest

Bigger angle, faster v, and vice versa. Same angle, same v:

wave- fronts:

rays:

Through an opening:

Images in a flat mirror m: Same size Same distance

i =^ r

always same as on other side of barrier

m

d

boundary

v 1 v 2

n 1 n 2

meson: s u

hadrons & leptons (which occur by themselves)

baryon:

u d u

Some of photon E and momentum are transferred to e-. ET and pT are conserved e-^ gains what photon loses

uud = (+2/3)e + (+2/3)e + (-1/3)e = +1e (a proton)

24. Standard model: All matter is made of…

su = (- 1 /3)e + (- 2 /3)e = - 1e

The antiparticles are: uud = - 1e and su = +1e They have the same mass as their antimatter.

i (^) r

o (^) i

specular:

diffuse:

**19. Diffraction:

  1. Reflection:
  2. Wavefronts entering a new medium** in which its speed is slower v 1 > v 2 (a wave traffic jam):

Compare: v 1 > v 2 (given), n 2 > n 1 , A 1 > A 2 (some reflected), 1 > 2 , but f 1 = f 2 (same frequency!)

23. Photon-electron collisions (Compton Effect)  Light acting like a particle:

After:

Smaller or bigger d:  Less diffraction