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Advanced Physics Semester 2 Final Study Guide
Momentum
1.
2.
3.
4.
The momentum of an object depends on mass and velocity.
Momentum is how hard it is to stop an object that is moving.
Momentum is a (vector/scalar) quantity. vector – it has magnitude and direction
Write a sentence that uses the word “momentum” that demonstrates that you know the meaning of
the word. It does not have to relate to science. After the big win in Ohio, the presidential candidate
gained lots of “momentum” and was very tough to beat.
5. What is the relationship between momentum and impulse? Change in momentum = impulse
6. What is the momentum of a 12 kg object traveling at a constant speed of 2 m/s? 12kg ∙2 m/s = 24
kg∙m/s
7. Which has more momentum:
a. A 1100 kg car moving 10 m/s = 11,000 kg∙m/s This one has the most momentum.
b. A 200 kg motorcycle moving 45 m/s = 9,000 kg∙m/s
c. A 2300 kg truck at rest = 2300 kg ∙0 m/s = 0
8. A force of 300 N causes a 20 kg cart to change its velocity from 3 m/s to 18 m/s. Determine the
impulse experienced by the cart. Impulse = ∆p = m ∆v = 20 kg ∙ 15 m/s = 300 kg∙m/s
9. A 1000 kg car is brought from 30 m/s to 15 m/s over a period of 3.0 seconds. Determine the force
experienced by the car. Ft = m ∆v F (3.0s) = 1000 kg (-15 m/s) = -5000 N
10. A skateboarder (m = 60 kg) collides with a 9.0 kg trashcan that is at rest.
a. Which object experiences the greatest force? same
b. Which object experiences the greatest impulse? same
c. Which object experiences the greatest change in momentum? same
d. Which object experiences the greatest change in velocity? trashcan
e. Which object experiences the greatest acceleration? trashcan
11. In boxing, boxers are often told to “roll with the punch.” Explain what this means in terms of
impulse. Change in momentum = impulse. When they “roll with the punch” the change in
momentum/impulse does not change. However, they are extending the time of impact. Impulse =
force x time. So if impulse doesn’t change and the time of impact is increased, then that means
that the force of impact is lessened.
12. True or False: In a collision, there is a bigger change in momentum when bouncing occurs. True.
When bouncing occurs, there is a bigger change in velocity, therefore a bigger momentum change.
13. A 0.80 kg soccer ball experiences an impulse of 25 Ns when kicked. Determine the momentum
change if the contact between the ball and the foot is 0.05 seconds. 25Ns. Momentum change =
impulse
14. A 90 kg tight end moving 8.0 m/s encounters a 400Ns impulse. Determine the velocity change of
the tight end. Impulse = mΔv 400 Ns = 90 kgΔv Δv = 4.4 m/s
15. A ball with a mass of 1.2 kg hits is traveling at 3 m/s. It hits a wall and bounces back without losing
any kinetic energy. What is the ball’s change in momentum?
∆p = mΔv = 1.2 kg (-6 m/s) = -7.2 kg∙m/s
16. Jerome plays middle linebacker for South's varsity football team. In a game against cross-town rival
North, he delivered a hit to North's 82-kg running back, changing his eastward velocity of 5.6 m/s
into a westward velocity of 2.5 m/s.
a. Determine the initial momentum of the running back.82 kg (5.6 m/s) = 460 kg∙m/s
b. Determine the final momentum of the running back. 82 kg(-2.5 m/s) = -205 kg∙m/s
c. Determine the momentum change of the running back. 82 kg (-8.1 m/s) = -660 kg∙m/s
d. Determine the impulse delivered to the running back. Impulse = ∆p = -660 kg∙m/s
17. A 1200 kg car is travelling north at 23 m/s when it hits a much bigger truck with a mass of 2300kg
that is traveling south. After the collision, the vehicles stick together and travel south at 16 m/s.
How fast was the truck moving before the collision?
(1200 kg)(23 m/s) + (2300 kg) (x m/s) = (3500 kg) (-16 m/s) x = -36.3 m/s or 36.3 m/s south
18. A car possesses 20,000 kg·m/s of momentum. What would be the car's new momentum if ...
a. its velocity was doubled. 40,000 kg·m/s
b. its velocity was tripled. 60,000 kg·m/s
c. its mass was doubled (by adding more passengers and a greater load) 40,000 kg·m/s
d. both its velocity was doubled and its mass was doubled. 80,000 kg·m/s
19. A 0.50-kg cart (#1) is pulled with a 1.0-N force for 1 second; another 0.50 kg cart (#2) is pulled with
a 2.0 N-force for 0.50 seconds. Which cart (#1 or #2) has the greatest acceleration? Explain.
Cart #2: F= ma They have the same mass, but cart #2 has a greater force being applied to it, so it
will have a greater acceleration.
Circular Motion
1. Determine the force of gravitational attraction between the Earth and the moon. Their masses are
5.98 x 1024 kg and 7.26 x 1022 kg, respectively. The average distance separating the Earth and the
moon is 3.84 x 108 m. Determine the force of gravitational attraction between the Earth and the
moon. F = G m1m2/r2
F = 6.67 x10 -11Nm2/kg2 (5.98 x 1024 kg ) (7.26 x 1022 kg )/( 3.84 x 108 m)2 = 1.96 x 1020 N
2. Identify the type of force which causes the following bold-faced objects to travel along a circular
path.




a. gravity
b. normal
c. tension
d. applied
e. friction
f. spring
g. electrical
h. magnetic
f
An eraser is tied to a string swung in a horizontal circle.
a
The moon orbits the earth.
e
A car makes a sharp right-hand turn along a level roadway.
b
A roller coaster passes through a loop. Consider the car at the bottom of the
loop.
3. Which of the following statements are true of an object moving in a circle at a constant speed?
Include all that apply.
 The object experiences a force which has a component directed parallel to the direction of
motion. False; if the motion is in a circle at constant speed, the net force is perpendicular to
the direction of motion.
 Inertia causes objects to move in a circle. False; it is centripetal force which causes the
circular motion. Inertia (which is NOT a force) is merely the tendency of any moving object to
continue in its straight-line constant speed path.
 There can be a force pushing outwards on the object as long as the net force in inwards.
True; an object which moves in a circle must have a net inward force.

Because the speed is constant, the acceleration is zero. False; acceleration occurs when
there is a change in velocity. Since the direction of the velocity vector is changing, there is
an acceleration - an inward acceleration.
 The acceleration and the net force vector are directed perpendicular to each other. False;
the acceleration and net force are always directed in the same direction. In this case, F and
a are directed inward; this happens to be perpendicular to the tangential velocity vector.
 If the net force acting upon the object is suddenly reduced to zero, then the object would
suddenly depart from its circular path and travel tangent to the circle. True; if the net force
is 0 N, then the moving object will maintain its state of motion. At the instant that Fnet
becomes 0 N, the object is moving tangent to the circle.
 The acceleration of the object is directed tangent to the circle. False; the acceleration is
directed inwards; only the velocity is directed tangent to the circle.
4. Explain how something can be moving at a constant speed yet be accelerating at the same time.
Acceleration is any change in speed and/or DIRECTION. Even if it is moving at a constant speed, if
it is changing directions, it is accelerating.
5. In the diagram below, draw vector arrows (straight lines with arrowheads) which indicate the
following for an object which is moving in a clockwise circle.
 The net force at point A.
 the acceleration at point B.
 the velocity at point C.
6. Justin is driving his 1500-kg Camaro through a horizontal curve on a level roadway at a speed of 23
m/s. The turning radius of the curve is 65 m. Determine the minimum value of the coefficient of
friction which would be required to keep Justin's car on the curve.
Fc =mv2/r = (1500 kg)(23 m/s)2/65 m = 12000N Ff = μFN FN = (1500kg)(9.8 m/s2) = 15,000 N
12000N = μ 15,000 N μ = 0.8
7. Suppose that the force of attraction due to gravity between Planet X and Planet Y is “F”. What
would the force due to gravity be if….
 The distance between the 2 planets is doubled ¼ F
 The distance between the 2 planets is halved 4F
 The distance between the 2 planets is tripled 1/9 F
 The mass of planet X is doubled (original distance apart) 2F
 The mass of Planet X is tripled and the mass of Planet Y is halved.(orig distance apart) 1.5F
8. What is the linear speed of an object that is spinning on a merry-go-round if it is completing 26
rotations per minute and the object is 35 cm from the axis of rotation?
26 rot/min x 2 π (0.35 m)/rot x 1min/60 sec = 0.95 m/s
9. What is the acceleration of the object in the previous problem?
ac = v2/r = (0.95 m/s)2/0.35 m = 2.6 m/s2
10. Kara Lott is practicing winter driving in the GBS parking lot. Kara turns the wheel to make a lefthand turn but her car continues in a straight line across the ice. Teacher A and Teacher B had
viewed the phenomenon. Teacher A argues that the lack of a frictional force between the tires and
the ice results in a balance of forces that keeps the car traveling in a straight line. Teacher B
argues that the ice placed an outward force on the tire to balance the turning force and thus keep
the car traveling in a straight line. Which teacher is the physics teacher? Explain the fallacy in the
other teacher's argument. Teacher A is the physics teacher. It is the lack of centripetal force that
causes the car to travel in a straight line.
Simple Harmonic Motion
1. A force of 12.0 N, when applied to a spring, compresses it a distance of 25 cm. What is the spring
constant? F = kx 12N = k (0.25m)
k = 48 N/m
2. When a mass of 2.40 kg is hung on a certain spring, the spring stretches out 60.0 cm. What is the
spring constant of the spring? F=( 2.40 kg) (9.8 m/s2) = 23.5 N
23.5 N = k (0.600) k = 39.2 N/m
3. A spring has a spring constant of 200 N/m. A 10.0kg object travelling at 5m/s strikes the spring.
a.) Calculate how far the spring will be compressed before the mass is brought to rest.
KE = 1/2mv2 = ½ (10.0 kg)(5 m/s)2 = 125J PE = ½ kx2 125J = ½ (200N/m) x2 x = 1.12 m
b.) What is the velocity of the mass when the spring is only compressed 0.40 meters?
PE = ½ kx2 PE = ½ (200N/m) (0.40m)2 PE = 40 J
KE = 125 J – 40J = 85 J 85 J = ½ (10.0 kg) (v2) v= 4.12 m/s
4. What are the definitions of period and frequency and what is the relationship between the two.
Period- the time it takes to complete one cycle Frequency – the # of cycles per second.
T = 1/f
f = 1/T
5. What is the frequency of a pendulum that makes 32 complete cycles in 45 seconds? What is the
period of the pendulum? f = 0.71 Hz and T = 1.4 s
6. What happens to the period of a pendulum when string length is increased? When mass is
increased? Increased string length = increased period & increased mass = no effect on period
7. A 0.005 kg bob is hung from the end of a string and is released from an amplitude of 30°. How long
must the string be if the desired period is 4.6 seconds?
Tp = 2 π √l/g
4.6 s = 2 π √l/9.8 m/s2 l = 5.3 m
8. If 100J of work is done in compressing a spring whose constant is 250 N/m, find the distance the
spring was compressed. 100 J = ½ kx2 100 J = ½ (250N/m) x2 x= 0.89 m
Sound & Waves
1. What is the Doppler Effect? The apparent change in frequency (pitch) when the distance between
the observer and wave source changes.
2. How many times more intense is a sound of 120 dB compared to 60 dB? 1,000,000 times greater
3. What is resonance? Resonance occurs when an object is forced to vibrate at its natural frequency
and an increase in amplitude occurs. What are some of the examples that we discussed in class?
Breaking a wine glass by sound waves & Tacoma Narrows Bridge collapse
4. Why do you see fireworks before you hear the boom? Light travels MUCH faster than sound
waves. (300,000,000 m/s vs 344 m/s)
5. What is interference? Interference is the combining of waves – two waves taking up the same
space at the same time
6. What is the difference between constructive interference and destructive interference?
Constructive inference occurs when the combining waves have a displacement in the same
direction. It produces a wave with a greater amplitude. Destructive interference occurs when the
combining waves have a displacement in the opposite direction. It produces a wave with a smaller
amplitude
7. What is the difference between a transverse and longitudinal wave? Transverse waves are waves
in which the medium moves perpendicular to the direction of the wave, while a longitudinal wave is
a wave in which the medium moves in the same direction as the direction of the wave.
8. What is a standing wave? A standing wave occurs when a reflected wave interferes with a incident
wave in a way that it looks like the wave is standing still.
9. How does temperature affect the speed of sound in air? As air temperature increases, the speed of
sound increases.
10. A periodic and repeating disturbance in a lake creates waves which emanate outward from its
source to produce circular wave patterns. If the frequency of the source is 2.00 Hz and the wave
speed is 5.00m/s then the distance between adjacent wave crests is ___ meter. 2.5 m
11. As a wave goes from one snakey (long skinny slinky) to another snakey, its wavelength gets longer.
How does this affect the frequency of the wave? Frequency does not change. The speed of the
wave? Speed increases.
Electricity & Magnetism
1. How many electrons have a charge of negative one Coulomb?
-1C = (1.6 x10-19C) (x) x = 6.25 x1018
2. Gravitational forces are always attractive. Explain how electrical forces are different. Electrical
forces can be attractive or repulsive.
3. Calculate the electric force between two point charges that are separated by 0.1 m. q1 = +0.2 C and
q2 = +0.4 C
Felec= k q1q2/r2 Felec = 9.0 x109 Nm2/C2 (0.2C)(0.4 C) /(0.1m)2 = 7.2 x1010 N
4. The electron and proton of a hydrogen atom have an average separation of 5.3 x 10-11 meters.
Calculate the gravitational force (Fg) and electric force (Felectric).
Fgrav = 6.67 x10 -11Nm2/kg2 (1.67 x10-27kg)(9.11 x10-31kg)/(5.3 x 10-11m) 2 = 3.61 x10-47 N
Felec = 9.0 x109 Nm2/C2(1.60 x10-19C)(-1.60 x10-19C)/ (5.3 x 10-11m) 2 = 8.2 x 10-8N
5. A small cork with an excess charge of +6.0 µC (1µC = 10-6C) is placed 0.12 m from another cork
that carries a charge of -4.3 µC.
a. What is the magnitude of the electric force between the corks?
Felec = 9.0 x109 Nm2/C2(6.0 x10-6C)(-4.3 x10-6C)/ (0.12 m) 2 = -16.1N
b. Is this force attractive or repulsive? attractive
c. How many excess electrons are on the negative cork?
-4.3 x10-6 C = -1.6 x 10-19 C (x) x = 2.7 x1014 electrons
d. How many electrons has the positive cork lost? 2.7 x 1014 electrons
6. Two electrostatic point charges of +60.0 µC and +50.0 µC exert a repulsive force on each other of
175N. What is the distance between the two charges?
175 N = (9.0 x109 Nm2/C2)(60.0 x10-6C)(50.0 x10-6C)/d2 d = 0.15 m
7. How many electrons must be removed from a neutral, isolated conducting sphere to give it a
positive charge of 8.0 x 10-8 C? 8.0 x10-8 C = 1.6 x 10-19 C (x)
x = 5.0 x 1011 electrons
8. What happens to the force between 2 charges as they get closer together? The force increases.
Farther apart? The force decreases.
9. What is the difference between electric insulators and conductors? Conductors are materials that
permit electrons to flow freely from particle to particle.
10. Understand how a leaf electroscope works.
11. What is the difference AC and DC current? In direct current (DC), the electric charge (current) only
flows in one direction. Electric charge in alternating current (AC), on the other hand, changes
direction periodically.
12. What is the difference between series and parallel circuits? A series circuit has only one possible
path for the electricity to flow while a parallel circuit has one or more paths.
MSC
1. What is the Big Bang Theory? The Big Bang Theory is the leading explanation about how the
universe began. At its simplest, it talks about the universe, as we know it, starting with a small
singularity, then inflating over the next 13.8 billion years to the cosmos that we know today.
2. What evidence is there to support the Big Bang Theory?
 Red shift
 Cosmic Microwave Background Radiation
 Abundance of different elements
3. What is global warming?
Global warming is the gradual heating of Earth's surface, oceans and atmosphere.
4. What is the greenhouse effect?
The Earth is constantly bombarded with enormous amounts of radiation, primarily from the sun. This
solar radiation strikes the Earth's atmosphere in the form of visible light, plus ultraviolet (UV),
infrared (IR) and other types of radiation that are invisible to the human eye. Incoming UV radiation
easily passes through the atmosphere (glass of greenhouse); however the Earth’s surface absorbs
much of this radiation and re-emits it as infrared radiation. Infrared radiation is weaker and has
difficulty passing through the certain molecules in the atmosphere such as CO2. The heat is
trapped inside, thus warming the greenhouse.