Mr C's AP1 Physics Final A

A rope is used to keep a 12 kg box sliding with a speed of 2 m/s in a circle with a radius of 3 m.  What is the centripetal acceleration on the box?

• .75 m/s²
• 1.33 m/s²
• .66 m/s²
• 1.5 m/s²

A person driving a car suddenly applies the brakes.  The car takes 4 s to come to rest while traveling 20 m 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 dividing the distance by the time.
• Yes, by determining the average speed while braking and doubling it.
• No, because the acceleration is needed to use standard equations like
  Δx = v_it + 1/2at².
• No, because the fundamental relationship that defines velocity contains acceleration.

A small space capsule at rest in distant outer space has two robots bolted to the floor inside.  For an experiment, one robot pushes forward on the front wall of the capsule with a force of 200 N, while the other robot pushes backward on the rear wall with a force of 500 N.  Which of the following best describes the resulting effects on the space capsule's motion?

• The capsule begins moving forward
• The capsule begins moving upwards
• The capsule does not begin moving
• The capsule begins moving backward

A ball of radius, R, rolls without slipping down a series of hills.  Beyond the starting point, at what peak or valley is the kinetic energy minimized?

• h₂
• h₃
• h₅
• h₆

The graphs represent the position, x, velocity, v, and acceleration, a, as functions of time for a marble moving in one dimension.  Which of the following could describe the motion of the marble?

• Rolling along the floor and then bouncing off a wall.
• Rolling down one side of a bowl and then rolling up the other side.
• Rolling up a ramp and then rolling back down.
• Falling and then bouncing elastically off a hard floor.

A group of students wish to determine the launch speed of a projectile launching device.  They will launch a projectile horizontally from atop a table of known height above the floor.  Which one of the following sets of additional measurements would be adequate (without any extraneous or unnecessary measurements) to allow the group to determine the launching speed?

• The horizontal displacement of the projectile.
• The horizontal displacement of the projectile and the time in the air.
• The time in the air and the mass of the projectile.
• The horizontal displacement, the time in the air, and the mass of the projectile.

A 5 kg ball is pushed back against a large horizontally oriented spring with k = 1000 N/m until the spring is compressed 50 cm from its initial equilibrium length.  The ball is then released from rest and launched horizontally.  What is the "launch speed" of the ball (as it passes back through the spring's equilibrium length)?

• 3.2 m/s
• 7.1 m/s
• 10 m/s
• 50 m/s

A certain component of a space probe has a mass of 10 kg on Earth.  What would be the weight of this same component, if weighed on the surface of a planet with 1/5 the mass and 1/2 of the radius of Earth?

• 8 N
• 10 N
• 40 N
• 80 N

Rank the position vs time graphs from greatest average velocity to least average velocity.

• A,B,C
• C,B,A
• B,A,C
• C,A,B

What is a quantity that tells only magnitude?

• Vector
• Weight
• Momentum
• Scalar