Physics
Chapter 2 Review
Name: _________________
Date: _______ Period:_____
1. Speed is __D__.
a. a measure of how fast something is moving.
b. the distance covered per unit time
c. always measured in terms of a unit of distance divided by a unit of time
d. all of the above
e. none of the above
2. One possible unit of speed is __D__.
a. miles per hour
b. kilometers per hour
c. light years per century
d. all of the above
e. none of the above
3. When you look at the speedometer in a moving car, you can see the car’s __A__.
d. instantaneous acceleration
a. instantaneous speed.
e. average distance traveled
b. average speed
c. average acceleration
4. Acceleration is defined as the rate of change in __B__.
a. distance
b. velocity
c. time it takes to move from one speed to another speed
d. time it takes to move from one place to another place
e. displacement
5. Suppose you are in a car that is going around a curve. The speedometer reads a constant 30 miles per hour.
Which of the following is NOT true?
a. You and the car are accelerating.
b. Your speed is constant.
c. Your velocity is constant.
d. Your acceleration is constant.
e. Your direction is constantly changing.
6. An object travels 8 m in the first second of travel, 8 m again during the second second of travel, and 8 m again
during the third second of travel. Its acceleration is __A__.
a. 0 m/s2
d. 32 m/s2
2
b. 8 m/s
e. none of the above
c. 16 m/s2
7. Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car’s average acceleration?
a. 0.25 m/s2
d. 10 m/s2
2
b. 2.5 m/s
e. 40 m/s2
2
c. 4.0 m/s
8. As an object falls freely in a vacuum, its __A__.
a. velocity increases
b. acceleration increases
c. all of the above
d. none of the above
9. In the absence of air resistance, objects fall at constant __C__.
a. velocity
b. speed
c. acceleration
d. distances each successive round
e. all of the above
10. A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of
the ball when caught would be
a. more than the speed it had when thrown upwards
b. less than the speed it had when thrown upwards
c. the same as the speed it had when thrown upwards
11. Suppose an object is in free fall. Each second the object falls __D__.
a. with the same average speed
b. with the same instantaneous speed
c. the same distance as in the second before
d. a larger distance than in the second before
e. none of the above
12. If you drop a feather and a coin at the same time in a tube filled with air, which will reach the bottom of the
tube first?
a. the coin
b. the feather
c. neither-they will reach the bottom at the same time
13. A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During
this time, the acceleration of the ball is always __D__.
a. in the direction of motion
b. opposite its velocity
c. directed upward
d. directed downward
14. When the ball reaches its highest point, its instantaneous speed is __A__.
a. 0 m/s
c. about 10 m/s
b. about 5 m/s
d. about 20 m/s
15. When the ball reaches its highest point, its acceleration is __C__.
a. 0 m/s2
b. about 5 m/s2
c. about 10 m/s2
d. about 20 m/s2
16. If you drop a feather and a coin at the same time in a vacuum tube, which will reach the bottom first?
a. the coin
b. the feather
c. neither-they will reach the bottom at the same time
True of
T
F
T
F
T
F
F
T
F
F
False:
17. The rate at which distance is covered is called speed.
18. Average speed is defined as the time it takes for a trip divided by the distance.
19. Velocity is different from speed in that velocity is speed given direction.
20. The SI unit of velocity is the meter.
21. The rate at which velocity changes with time is called acceleration.
22. The SI unit of acceleration is m/s.
23. When a car rounds a corner at constant speed, its acceleration is zero.
24. Even though a car is slowing down, it is still accelerating, in the most general definition of acceleration.
25. A ball is thrown into the air. At the highest point, the ball has zero velocity and zero acceleration.
26. As a ball falls freely, the distance it falls each second is the same.
Problems:
27. What is the average speed of a cheetah that runs 65 m in 3.0 seconds?
v=
∆x 65m
=
= 21.7 m s
∆t 3 . 0 s
28. What is the average acceleration of a car that goes from rest to 59 km/h in 9.0 seconds?
a=
∆v 16.4 m s
=
= 1.82 m s 2
∆t
9 .0 s
30. How much time does a car with an acceleration of 4.0 m/s2 take to go from 10 m/s to 30 m/s?
a=
v f − vi
∆t
⇒ ∆t =
v f − vi
a
=
30 m s − 10 m s
= 5s
4 m s2
31. How far did the car travel?
∆x =
1
2
(v
i
+ v f )∆t =
1
2
(10 m s + 30 m s )5s = 100m
32. An apple falls from a tree and 0.5 seconds later hits the ground. How fast is the apple falling when it hits the
ground?
v f = vi + a∆t = 0 + −9.8 m s 2 (0.5s ) = −4.9 m s
33. How far did that apple fall?
∆x =
1
2
(v
i
+ v f )∆t =
1
2
(0 m s + (− 4.9 m s ))(0.5s ) = −1.23m
34. Starting from rest, a car undergoes a constant acceleration of 6.0 m/s2. How far will the car travel in the first
second?
∆x = vi ∆t + 12 a∆t 2 = 0 + 12 (6.0 m s )(1s ) = 3m
2
35. A stone is dropped from a cliff. After it has fallen 40 m, what is the stone’s velocity?
v f = vi + 2a∆y = 0 + 2(− 9.8 m s 2 )(− 40m ) = −28 m s
2
2
36. Describe the acceleration in the following situations:
a.
b.
velocity
velocity
8
8
6
6
neg
0.
pos
Pos(slowing) Pos(increasing)
4
4
2
2
velocity
time
time
14
2
4
6
8
10
12
37. Use the v/t
the following
2
4
6
8
a. What is the displacement of the object after 2 s?
20m
10
8
6
4
2
time
2
4
6
10
graph to answer
questions.
b. What is the average acceleration in the time interval t = 0 s to t = 2 s?
5m/s2
c. What is the average acceleration in the time interval t = 2 s to t = 4 s?
0
d. What is the average acceleration in the time interval t = 4 s to t = 6 s?
-5m/s2
38. Use the following p/t graph to answer the questions.
a. What is the total displacement of the object?
position
9
7.5m
8
7
b. What is the average velocity of the object?
6
0.75m/s
5
4
3
c. What is the average acceleration of the object?
0
2
1
time
1
2
3
4
5
6
7
8
9
10