Name: ________________
Physics
Date: ___________
Test Review: Free Fall and Projectile Motion
1. A rock is dropped from a bridge. What happens to the
magnitude of the acceleration and the speed of the rock
as it falls? [Neglect friction.]
A)
B)
C)
D)
Both acceleration and speed increase.
Both acceleration and speed remain the same.
Acceleration increases and speed decreases.
Acceleration remains the same and speed
increases.
2. Which graph best represents the relationship between the acceleration of an object falling freely near the
surface of Earth and the time that it falls?
A)
B)
C)
D)
3. An object is dropped from rest and falls freely 20. meters
to Earth. When is the speed of the object 9.8 meters per
second?
A)
B)
C)
D)
during the entire first second of its fall
at the end of its first second of fall
during its entire time of fall
after it has fallen 9.8 meters
4. A 4.0-kilogram rock and a 1.0-kilogram stone fall freely
from rest from a height of 100 meters. After they fall for
2.0 seconds, the ratio of the rock's speed to the stone's
speed is
A) 1:1
B) 1:2
C) 2:1
D) 4:1
5. A rock dropped off a bridge takes 5 seconds to hit the
water. Approximately what was the rock's velocity just
before impact?
A) 5 m/s
C) 50 m/s
B) 2 m/s
D) 125 m/s
6. An object dropped from rest will have a velocity of
approximately 30. meters per second at the end of
A) 1.0 s
B) 2.0 s
C) 3.0 s
D) 4.0 s
7. Which graph best represents the motion of a freely
falling body near the Earth's surface?
A)
B)
C)
D)
8. A ball is thrown vertically upward with an initial
velocity of 29.4 meters per second. What is the
maximum height reached by the ball? [Neglect friction.]
A) 14.7 m
C) 44.1 m
B) 29.4 m
D) 88.1 m
9. A book of mass m falls freely from rest to the floor from
the top of a desk of height h. What is the speed of the
book upon striking the floor?
A)
B)
C)
D)
10. A ball is thrown straight downward with a speed of
0.50 meter per second from a height of 4.0 meters.
What is the speed of the ball 0.70 second after it is
released? [Neglect friction.]
A) 0.50 m/s
C) 9.8 m/s
16. As shown in the diagram below, a student standing on
the roof of a 50.0-meter-high building kicks a stone at a
horizontal speed of 4.00 meters per second.
B) 7.4 m/s
D) 15 m/s
11. What is the speed of a 2.5-kilogram mass after it has
fallen freely from rest through a distance of 12 meters?
A) 4.8 m/s
C) 30. m/s
B) 15 m/s
D) 43 m/s
12. A rock falls from rest off a high cliff. How far has the
rock fallen when its speed is 39.2 meters per second?
[Neglect friction.]
A) 19.6 m
C) 78.3 m
B) 44.1 m
D) 123 m
13. A softball is thrown straight up, reaching a maximum
height of 20 meters. Neglecting air resistance, what is
the ball's approximate vertical speed when it hits the
ground?
A) 10 m/sec
C) 15 m/sec
B) 20 m/sec
D) 40 m/sec
14. A rock falls freely from rest near the surface of a planet
where the acceleration due to gravity is 4.0 meters per
second 2. What is the speed of this rock after it falls 32
meters?
A) 8.0 m/s
C) 25 m/s
B) 16 m/s
D) 32 m/s
How much time is required for the stone to reach the
level ground below? [Neglect friction.]
A) 3.19 s B) 5.10 s C) 10.2 s D) 12.5 s
17. An astronaut standing on a platform on the Moon drops
a hammer. If the hammer falls 6.0 meters vertically in
2.7 seconds, what is its acceleration?
A) 1.6 m/s 2
C) 4.4 m/s 2
B) 2.2 m/s 2
D) 9.8 m/s 2
18. A 1.0-kilogram ball is dropped from the roof of a
building 40. meters tall. What is the approximate time
15. A 5.0-kilogram sphere, starting from rest, falls freely 22
of fall? [Neglect air resistance.]
meters in 3.0 seconds near the surface of a planet.
A) 2.9 s B) 2.0 s C) 4.1 s D) 8.2 s
Compared to the acceleration due to gravity near
Earth's surface, the acceleration due to gravity near the
19. A ball is thrown horizontally at a speed of 24 meters
surface of the planet is approximately
per second from the top of a cliff. If the ball hits the
ground 4.0 seconds later, approximately how high is
A) the same
B) twice as great
the cliff?
C) one-half as great D) four times as great
A) 6.0 m B) 39 m C) 78 m D) 96 m
20. A ball dropped from rest falls freely until it hits the
ground with a speed of 20 meters per second. The time
during which the ball is in free fall is approximately
A) 1 s
B) 2 s
C) 0.5 s
D) 10 s
21. How far will a brick starting from rest fall freely in 3.0
seconds?
A) 15 m B) 29 m C) 44 m D) 88 m
22. A ball is thrown straight up with a speed of 12 meters
per second near the surface of Earth. What is the
maximum height reached by the ball? [Neglect air
friction.]
A) 15 m
C) 1.2 m
B) 7.3 m
D) 0.37 m
23. In an experiment that measures how fast a student
reacts, a meter stick dropped from rest falls 0.20 meter
before the student catches it. The reaction time of the
student is approximately
A) 0.10 s B) 0.20 s C) 0.30 s D) 0.40 s
24. Starting from rest, object A falls freely for 2.0 seconds,
and object B falls freely for 4.0 seconds. Compared
with object A, object B falls
A) one-half as far
C) three times as far
B) twice as far
D) four times as far
25. A baseball is thrown at an angle of 40.0° above the
horizontal. The horizontal component of the baseball’s
initial velocity is 12.0 meters per second. What is the
magnitude of the ball’s initial velocity?
A) 7.71 m/s
C) 15.7 m/s
B) 9.20 m/s
D) 18.7 m/s
26. Two spheres, A and B, are simultaneously projected
horizontally from the top of a tower. Sphere A has a
horizontal speed of 40. meters per second and sphere B
has a horizontal speed of 20. meters per second. Which
statement best describes the time required for the
spheres to reach the ground and the horizontal distance
they travel? [Neglect friction and assume the ground is
level.]
A) Both spheres hit the ground at the same time and
at the same distance from the base of the tower.
B) Both spheres hit the ground at the same time,
but sphere A lands twice as far as sphere B
from the base of the tower.
C) Both spheres hit the ground at the same time, but
sphere B lands twice as far as sphere A from the
base of the tower.
D) Sphere A hits the ground before sphere B, and
sphere A lands twice as far as sphere B from the
base of the tower
27. Base your answer to the following question on the information and diagram below. A student standing on a knoll throws a snowball horizontally 4.5 meters above the level ground
toward a smokestack 15 meters away. The snowball hits the smokestack 0.65 second after being
released. [Neglect air resistance.]
At the instant the snowball is released, the horizontal component of its velocity is approximately
A) 6.9 m/s
B) 9.8 m/s
C) 17 m/s
28. Base your answer to the following question on the information below.
A ball is projected vertically upward from the surface of
the Earth with an initial speed of +49 meters per
second. The ball reaches its maximum height in 5.0
seconds. (Disregard air resistance.)
What is the total displacement of the ball from the time
it is thrown until it returns to the point from which it
was thrown?
A) 248 m B) 9.8 m C) 49 m D) 0 m
29. Which graph best represents the relationship between
the velocity of an object thrown straight upward from
Earth’s surface and the time that elapses while it is in
the air? [Neglect friction.]
A)
B)
C)
D)
D) 23 m/s
30. A 0.2-kilogram red ball is thrown horizontally at a
speed of 4 meters per second from a height of 3 meters.
A 0.4-kilogram green ball is thrown horizontally from
the same height at a speed of 8 meters per second.
Compared to the time it takes the red ball to reach the
ground, the time it takes the green ball to reach the
ground is
A) one-half as great
C) the same
B) twice as great
D) four times as great
Base your answers to questions 31 and 32 on the information and diagram below.
A child kicks a ball with an initial velocity of 8.5 meters
per second at an angle of 35° with the horizontal, as
shown. The ball has an initial vertical velocity of 4.9
meters per second and a total time of flight of 1.0
second. [Neglect air resistance.]
31. The horizontal component of the ball's initial velocity is
approximately
A) 3.6 m/s
C) 4.9 m/s
B) 7.0 m/s
D) 13 m/s
32. The maximum height reached by the ball is
approximately
A) 1.2 m B) 2.5 m C) 4.9 m D) 8.5 m
Base your answers to questions 33 through 35 on the information and graph below.
A machine fired several projectiles at the same angle, , above the horizontal. Each projectile
was fired with a different initial velocity, vi. The graph below represents the
relationship between the magnitude of the initial vertical velocity, viy, and the magnitude of
the corresponding initial velocity, vi, of these projectiles
33. Determine the angle, , above the horizontal at which the projectiles were fired.
34. Determine the magnitude of the initial vertical velocity of the projectile, v iy, when the magnitude of its
initial velocity, v i, was 40. meters per second.
35. Calculate the magnitude of the initial horizontal velocity of the projectile, v ix, when the magnitude of its
initial velocity, v i, was 40. meters per second. [Show all work, including the equation and substitution with
units.]
Base your answers to questions 36 through 38 on the information below.
The path of a stunt car driven horizontally off a cliff is represented in the diagram below. After
leaving the cliff, the car falls freely to point A in 0.50 second and to point B in 1.00 second.
36. Calculate the magnitude of the vertical displacement, d y, of the car from point A to point B. [Neglect
friction.] [Show all work, including the equation and substitution with units.]
37. Determine the magnitude of the vertical velocity of the car at point A.
38. Determine the magnitude of the horizontal component of the velocity of the car at point B. [Neglect
friction.]
Base your answers to questions 39 through 41 on the information below.
A projectile is launched into the air with an initial speed of vi at a launch angle of 30.° above the
horizontal. The projectile lands on the ground 2.0 seconds later.
39. How does the total horizontal distance traveled by the projectile change as the launch angle is increased
from 30.° to 45° above the horizontal? [Assume the same initial speed, v i.]
40. How does the maximum altitude of the projectile change as the launch angle is increased from 30.° to 45°
above the horizontal? [Assume the same initial speed, v i .]
41. On the diagram above, sketch the ideal path of the projectile.
Base your answers to questions 42 through 44 on the information below.
A projectile is fired from the ground with an initial velocity of 250. meters per second at an angle of
60.° above the horizontal.
42. Explain why the projectile has no acceleration in the horizontal direction. [Neglect air friction.]
43. Determine the horizontal component of the initial velocity.
44. On the diagram above, use a protractor and ruler to draw a vector to represent the initial velocity of the
projectile. Begin the vector at point P, and use a scale of 1.0 centimeter = 50. meters per second.
Base your answers to questions 45 through 47 on the
information and diagram below.
A projectile is launched horizontally at a speed of
meters per second from a platform located a
vertical distance above the ground. The projectile
strikes the ground after time at horizontal distance from the base of the platform. [Neglect friction.]
46. Calculate the horizontal distance, , if the projectile's
total time of flight is seconds. [Show all work,
including the equation and substitution with units.]
47. On the diagram provided, sketch the theoretical path of
the projectile.
48. A projectile has an initial horizontal velocity of 15
meters per second and an initial vertical velocity of 25
meters per second. Determine the projectile’s
horizontal displacement if the total time of flight is 5.0
seconds. [Neglect friction.]
49. Base your answer to the following question on the
information below and your knowledge of physics.
A punter in a football game kicks a ball from the goal
line at an angle of 60 o above the horizontal with a
velocity of 25 m/s.
What is the hang time of the punt?
How far down the field does the ball land?
45. Express the projectile's total time of flight, , in terms
of the vertical distance, , and the acceleration due to
gravity, . [Write an appropriate equation and solve it
for .]
50. A rescue pilot drops a survival kit while her plane is
flying at an altitude of 2000.0 m with a forward
velocity of 100.0 m/s. If air friction is disregarded, how
far in advance of the starving explorer's drop zone
should she release the package?
Answer Key
3.9.TR Free Fall and Projectile Motion
1.
D
2.
D
3.
B
37.
4.9 m/s
4.
A
38.
16 m/s
5.
C
39.
6.
C
The total horizontal
distance will increase.
7.
D
40.
8.
C
The projectile’s
maximum altitude
will increase.
9.
A
10.
B
11.
B
12.
C
13.
B
14.
B
15.
C
16.
A
17.
A
18.
A
19.
C
20.
B
21.
C
22.
B
23.
B
24.
D
25.
C
26.
B
27.
D
28.
D
29.
D
30.
C
31.
B
32.
A
33.
39º 2º
34.
25 m/s 1 m/s.
35.
36.
46.
41.
42.
43.
44.
45.
Examples: – no force
on object in
horizontal direction –
The only force is
vertically. – Gravity
acts only vertically.
125 m/s ( 10 m/s)
47.
48.
75 m
49.
4.41 s, 55.2 m
50.
2020 m