AP PHYSICS FINAL REVIEW

(Circular Motion/Universal Gravitation)

A ball attached to a string is whirled around in a horizontal circle having radius R. If the radius of the circle is changed to 4R and the same centripetal force is applied by the string, the speed of the ball is what fraction of the original speed?

1/4 of the original speed

(Circular Motion/Universal Gravitation)

A satellite of mass m and speed v moves in a stable, circular orbit around a planet of mass M. What is the radius of the satellite's orbit?

GM / v^2

(Projectile Motion)

An object is released from rest on a planet that has no atmosphere. The object falls freely for 3.0 m in the first second. What is the magnitude of the acceleration due to gravity?

6.0 m/s^2

(Kinematics)

When an object's initial velocity is positive and then has a negative acceleration, what happens to the object's motion?

The object slows down.

(Kinematics)

A person driving a car suddenly applies the brakes. The car takes 4 seconds to come to rest traveling 20 meters at a constant acceleration. Can the speed of the car immediately before the brakes were applied be determined without first determining the car's acceleration?

Yes, by determining the average speed while braking and doubling it.

(Constant Acceleration Dynamics)

As a ball falls, consider one force to be the pull of the earth on the ball. What is the 3rd law pair to this force?

The pull of the ball on the earth.

(Constant Acceleration Dynamics)

A 50 N box is at rest on a horizontal surface. The coefficient of static friction between the box and the surface is 0.50, and the coefficient of kinetic friction is 0.30. A horizontal 20 N force is then exerted on the box. The magnitude of the acceleration of the box is most nearly...

0 m/s^2

(Work and Energy)

A ball is dropped from rest and falls to the floor. The initial gravitational potential energy of the ball-earth-floor system is 10 J. The ball then bounces back up to a height where the gravitational potential energy is 7 J. What was the mechanical energy of the ball-earth-floor system the instant the ball left the floor?

10 J.

(Momentum)

A spring is compressed between two objects with unequal masses, m and M, and held together. The objects are initially at rest on a horizontal frictionless surface. What is the final momentum of the two objects?

0.

(Momentum)

In one-dimensional perfectly elastic collision, an object of mass m is traveling with speed v in a +x direction when it strikes an object with mass 3m that is at rest. What are the objects' velocities following the collision?

Object of Mass m: v/2, -x direction

Object of Mass 3m: v/2, +x direction

(Momentum)

2kg object traveling at 5 m/s on a frictionless horizontal surface collides head-on with and sticks to a 3kg object initially at rest. Which of the following correctly identifies the change in total KE and resulting speed of objects after collision?

KE: decreases

Speed: 2 m/s

(Simple Harmonic Motion)

Block 1 is attached to a spring and oscillates on a horizontal frictionless surface. When block 1 is at a point of max displacement, block 2 is placed on top of it from directly above without interrupting the oscillation, and the two blocks stick together. How do max KE and period of oscillation with both blocks compare to those of block 1 alone?

Max KE: the same

Period: greater

(Simple Harmonic Motion)

A block of known mass is hanging from an ideal spring of known spring constant is oscillating vertically. A motion detector records position, velocity, and acceleration of the block as a function of time. Which of the following indicates measured quantities that are sufficient to determine whether the net force exerted on block equals the vector sum of the individual forces?

acceleration and position only

(Simple Harmonic Motion)

Which of the following is true for a system consisting of mass oscillating on a the end of an ideal spring?

the max KE and max PE energy are equal, but occur at the same time

(Simple Harmonic Motion)

When an object is oscillating in SHM, at its max displacement from the equilibrium position, which of the following is true of the values of its speed and the magnitude of the restoring force?

Speed: zero

Restoring force: max

(Rotational Motion)

A satellite that is spinning cylinder has intital rotational inertia I and angular velocity. Solar panels unfold from the satelittle and are extended outward. The satellite then has rotational inertia If = aIo and angular velocity final = b(initial), where a and b are constants. Which of the following are true?

a > 1

b < 1

(Rotational Motion)

While traveling in its elliptical orbit around the sun, mars gains speed during the part of the orbit where it is getting closer to the sun. which of the following can be used to explain this gain in speed?

As mars gets closer to the sun, the mars sun system loses PE and mars gains KE

(Rotational Motion)

An ice skater is spinning about a vertical axis with arms fully extended. If the arms are pulled in closer to the body, which of the following ways are the angular momentum and KE of the skater affected?

Angular Momentum: remains constant

KE: increases

(Mechanical Waves and Sound)

Alan and Beverly are on opposite sides of a large room when alan says something to beverly. beverly does not hear him, so alan repeats the message louder and beverly now hears it. which of the following could be different about the second sound wave compared to the first that allows beverly to hear it?

the air molecules disturbed by the second wave undergo a greater displacement from their equilibrium positions

(Mechanical waves and sound)

a student wants to determine the speed of sound at an elevation of one mile. to do this the student performs an experiment to determine the resonance frequencies of a tube that's closed at one end. the student takes measurements everyday for a week and gets different on different days. which of the following experiments would help the student determine the reason for different results?

repeating the experiment on several 10C days and several 20C days

(Mechanical waves and sound)

to determine the speed of waves on a string, some students tie a long string of unknown length between a wave generator and a wall. they vary frequency f of the generator to get a standing wave. they count nodes n and measure wavelength. they repeat the experiment, creating standing waves with different frequencies. which of the following is the best relationship to graph to determine the speed of waves on the string?

f as a function of 1/wavelength

(mechanical waves and sound)

a musician stands outside in a field and plucks a string on an acoustic guitar. standing waves will most likely occur in which of the following media? select 2 answers

guitar string

air inside the guitar

(mechanical waves and sound)

suppose two square wave pulses that are in the same plane could be created on a string, one with a max displacement of 4 cm and the other with a max displacement of 2cm. which of the following is a possible displacement of the string when the wave pulses overlap? select 2

2 cm

6 cm

(Formulas & Concepts)

KE =

1/2mv^2

(Formulas & Concepts)

Ug (gravitational potential energy) =

mgh

Us (spring potential energy) =

1/2kx^2