AP PHYSICS 1 UNIT 5 PRACTICE TEST FR NAME_________________________________

Show your work for partial credit. Circle or box your answers. Include the correct units and

the correct number of significant figures in your answers!

1. The experimental apparatus

shown in the figure at right

contains a pendulum consisting

of a 0.66 kg ball attached to a

string of length 0.60 m. The

pendulum is released from rest at

an angle of 60º and collides with

a ball of mass 0.22 kg initially at

rest at the edge of a table. The

0.22 kg ball hits the floor a

distance of 1.4 m from the edge

of the table.

(a) Calculate the speed of the 0.66 kg ball just before the collision.

(b) Calculate the speed of the 0.22 kg ball immediately after the collision. Do not assume

the collision is elastic!

(c) Calculate the speed of the 0.66 kg ball immediately after the collision.

(d) Indicate the direction of motion of the 0.66 kg ball immediately after the collision.

_____ To the left _____ To the right

(e) Calculate the height to which the 0.66 kg ball rises after the collision.

(f) Based on your data, is the collision elastic?

_____ Yes _____ No Justify your answer.

2. Two identical objects 𝐴 and 𝐵 of mass 𝑀 move on a one-dimensional, horizontal air track. Object 𝐵 initially moves to the right with speed 𝑣0. Object 𝐴 initially moves to the right with speed 3𝑣0, so that it collides with object 𝐵. Friction is negligible. Express your answers in terms of 𝑀 and 𝑣0.

(a) Determine the total momentum of the system of the two objects.

(b) A student predicts that the collision will be totally inelastic (the objects stick together

on collision). Assuming this is true, determine the speed and direction of motion for the

two objects immediately after the collision.

(c) Determine the kinetic energy dissipated in this predicted collision.

When the experiment is performed, the student is surprised to observe that the objects

separate after the collision and that object 𝐵 subsequently moves to the right with a speed 2.5𝑣0.

(d) Determine the speed and direction of motion for object 𝐴 immediately after the collision.

(e) Compare the kinetic energy dissipated in the actual collision to the kinetic energy

dissipated in the predicted collision. Will it be greater, less, or the same? Justify your

answer.

3. A 2.00-kg object moves

along a straight line. The

met force acting on the

object varies with time as

shown in the graph at

right. The object starts

from rest at position 𝑥 = 0 m and time 𝑡 = 0 s.

(a) Determine the impulse given to the object from 𝑡 = 0 s to 𝑡 = 12 s.

(b) Determine the impulse given to the object from 𝑡 = 12 s to 𝑡 = 20 s.

(c) Find the velocity of the object at 𝑡 = 12 s.

2

Time (s)

(d) Find the velocity of the object at 𝑡 = 20 s.

(e) A different constant force acts on the object from 𝑡 = 20 s to 𝑡 = 30 s, bringing it back to rest. Graph this force as a function of time below.