Download Q1 CP Physics Answer Section

Q1 CP Physics Study Guide
𝒙𝒇 = 𝒙𝒊 + 𝒗𝒊 𝒕 +
𝟏 𝟐
𝒂𝒕
𝟐
𝒗𝒇 = 𝒗𝒊 + 𝒂𝒕
𝒗𝟐𝒇 = 𝒗𝟐𝒊 + 𝟐𝒂𝒙
∑ 𝑭 = 𝒎𝒂
𝑭𝒘 = 𝒎𝒈
𝒇 = 𝝁𝒎𝒈
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. A change in a physical quantity w having initial value wi and final value wf is given by which of the following?
a. wi - wf
b. wf - wi
c. (wf + wi)/2
d. none of the above
____
2. A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is the average
velocity?
a. 1.7 m/s
b. 2.5 m/s
c. 3.4 m/s
d. zero
____
3. A cheetah can run at approximately 100 km/hr and a gazelle at 80.0 km/hr. If both animals are running at full
speed, with the gazelle 70.0 m ahead, how long before the cheetah catches its prey?
a. 12.6 s
b. 25.2 s
c. 6.30 s
d. 10.7 s
____
4. A railroad train travels forward along a straight track at 80.0 m/s for 1 000 m and then travels at 50.0 m/s for the
next 1 000 m. What is the average velocity?
a. 65.0 m/s
b. 61.5 m/s
c. 63.7 m/s
d. 70.0 m/s
____
5. The distance of the Earth from the sun is 93 000 000 miles. If there are 3.15  107 s in one year, find the speed of
the Earth in its orbit about the sun.
a. 9.28 miles/s
b. 18.6 miles/s
c. 27.9 miles/s
d. 37.2 miles/s
____
6. On a position versus time graph, the slope of the straight line joining two points on the plotted curve that are
separated in time by the interval t, is which of the following quantities?
a. average steepness
b. average velocity
c. instantaneous velocity
d. average acceleration
____
7. A European sports car dealer claims that his car will accelerate at a constant rate from rest to 100 km/hr in 8.00
s. If so, what is the acceleration? (Hint: First convert speed to m/s.)
a. 3.47 m/s2
b. 6.82 m/s2
c. 11.4 m/s2
d. 17.4 m/s2
____
8. An x vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the
velocity of the ball is zero. We can be positive that at t  5 s,
a. the slope of the curve is non-zero.
b. the ball has stopped.
c. the acceleration is constant.
d. the curve is at x  0, t  0.
____
9. A v vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t  5 s the
acceleration of the ball is zero. We know that at t  5 s,
a. the slope of the curve is non-zero.
b. the velocity of the ball is not changing.
c. the curve is not crossing the time axis.
d. the curve is at v  0, t  0.
____ 10. The value of an object's acceleration may be characterized in equivalent words by which of the following?
a. displacement
b. rate of change of displacement
c. velocity
d. rate of change of velocity
____ 11. A 50-g ball traveling at 25.0 m/s is bounced off a brick wall and rebounds at 22.0 m/s. A high-speed camera
records this event. If the ball is in contact with the wall for 3.50 ms, what is the magnitude of the average
acceleration of the ball during this time interval?
a. 13 400 m/s2
b.
6 720 m/s2
c.
857 m/s2
d.
20 m/s2
____ 12. A ball is pushed with an initial velocity of 4.0 m/s. The ball rolls down a hill with a constant acceleration of 1.6
m/s2. The ball reaches the bottom of the hill in 8.0 s. What is the ball's velocity at the bottom of the hill?
a. 10 m/s
b. 12 m/s
c. 16 m/s
d. 17 m/s
____ 13. A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is the final
velocity after 11 s?
a. 1.8 m/s
b. 3.2 m/s
c. 5.1 m/s
d. zero
____ 14. A drag racer starts from rest and accelerates at 10 m/s2 for the entire distance of 400 m (1/4 mile). What is the
velocity of the race car at the end of the run?
a.
45 m/s
b.
89 m/s
c. 130 m/s
d. 180 m/s
____ 15. A Cessna aircraft has a lift-off speed of 120 km/hr. What minimum constant acceleration does this require if the
aircraft is to be airborne after a take-off run of 240 m?
a. 2.31 m/s2
b. 3.63 m/s2
c. 4.63 m/s2
d. 5.55 m/s2
____ 16. Two objects of different mass are released simultaneously from the top of a 20-m tower and fall to the ground.
If air resistance is negligible, which statement best applies?
a. The greater mass hits the ground first.
b. Both objects hit the ground together.
c. The smaller mass hits the ground first.
d. No conclusion can be made with the information given.
____ 17. A baseball is released at rest from the top of the Washington Monument. It hits the ground after falling for 6.0 s.
What was the height from which the ball was dropped? (g  9.8 m/s2 and assume air resistance is negligible)
a. 1.5  102 m
b. 1.8  102 m
c. 1.1  102 m
d. 2.1  102 m
____ 18. A rock, released at rest from the top of a tower, hits the ground after 1.5 s. What is the speed of the rock as it hits
the ground? (g  9.8 m/s2 and air resistance is negligible)
a. 15 m/s
b. 20 m/s
c. 31 m/s
d. 39 m/s
____ 19. Omar throws a rock down with speed 12 m/s from the top of a tower. The rock hits the ground after 2.0 s. What
is the height of the tower? (air resistance is negligible)
a. 20 m
b. 24 m
c. 44 m
d. 63 m
____ 20. Gwen releases a rock at rest from the top of a 40-m tower. If g  9.8 m/s2 and air resistance is negligible, what is
the speed of the rock as it hits the ground?
a.
28 m/s
b.
30 m/s
c.
56 m/s
d. 784 m/s
____ 21. At the top of a cliff 100 m high, Raoul throws a rock upward with velocity 15.0 m/s. How much later should he
drop a second rock from rest so both rocks arrive simultaneously at the bottom of the cliff?
a. 5.05 s
b. 3.76 s
c. 2.67 s
d. 1.78 s
____ 22. Mt. Everest is more than 8 000 m high. How fast would an object be moving if it could free fall to sea level after
being released from an 8000-m elevation? (Ignore air resistance.)
a.
396 m/s
b.
120 m/s
c.
1 200 m/s
d. 12 000 m/s
____ 23. A ball is thrown vertically upwards at 19.6 m/s. For its complete trip (up and back down to the starting position),
its average speed is:
a. 19.6 m/s.
b. 9.80 m/s.
c. 4.90 m/s.
d. not given.
____ 24. Which of the following is an example of a vector quantity?
a. velocity
b. temperature
c. volume
d. mass
____ 25. A helicopter is traveling at 40 m/s at a constant altitude of 100 m over a level field. If a wheel falls off the
helicopter, with what speed will it hit the ground? (g  9.8 m/s2 and air resistance negligible)
a. 40 m/s
b. 50 m/s
c. 60 m/s
d. 70 m/s
____ 26. If we know an object is moving at constant velocity, we may assume:
a. the net force acting on the object is zero.
b. there are no forces acting on the object.
c. the object is accelerating.
d. the object is losing mass.
____ 27. An astronaut applies a force of 500 N to an asteroid, and it accelerates at 7.00 m/s2. What is the asteroid's mass?
a.
71 kg
b.
135 kg
c.
441 kg
d. 3 500 kg
____ 28. A 70.0-kg man jumps 1.00 m down onto a concrete walkway. His downward motion stops in 0.0200 seconds. If
he forgets to bend his knees, what force is transmitted to his leg bones?
a. 15 500 N
b.
7 010 N
c.
4 900 N
d.
3 500 N
____ 29. Three forces, 5.0 N, 15.0 N, and 20.0 N, are acting on a 9.81-kg object. Which of the following forces could also
be acting on the object if it is moving with constant velocity?
a. 1.0 N
b. 19.0 N
c. 39.0 N
d. any of the above
____ 30. A 15-kg block rests on a level frictionless surface and is attached by a light string to a 5.0-kg hanging mass
where the string passes over a massless frictionless pulley. If g = 9.8 m/s2, what is the tension in the connecting
string?
a. 65 N
b. 17 N
c. 49 N
d. 37 N
____ 31. As a 3.0-kg bucket is being lowered into a 10-m-deep well, starting from the top, the tension in the rope is 9.8 N.
The acceleration of the bucket will be:
a. 6.5 m/s2 downward.
b. 9.8 m/s2 downward.
c. zero.
d. 3.3 m/s2 upward.
____ 32. Find the tension in an elevator cable if the 1 000-kg elevator is descending with an acceleration of 1.8 m/s2,
downward.
a.
5 700 N
b.
8 000 N
c.
9 800 N
d. 11 600 N
____ 33. A horizontal force of 750 N is needed to overcome the force of static friction between a level floor and a 250-kg
crate. What is the acceleration of the crate if the 750-N force is maintained after the crate begins to move and the
coefficient of kinetic friction is 0.12?
a. 1.8 m/s2
b. 2.5 m/s2
c. 3.0 m/s2
d. 3.8 m/s2
____ 34. Three identical 6.0-kg cubes are placed on a horizontal frictionless surface in contact with one another. The
cubes are lined up from left to right and a 36-N force is applied to the left side of the left cube causing all three
cubes to accelerate to the right. If the cubes are each subject to a frictional force of 6.0 N, what is the magnitude
of the force exerted on the middle cube by the left cube in this case?
a. 12 N
b. 24 N
c. 36 N
d. none of the above
____ 35. Three identical 6.0-kg cubes are placed on a horizontal frictionless surface in contact with one another. The
cubes are lined up from left to right and a 36-N force is applied to the left side of the left cube causing all three
cubes to accelerate to the right. If the cubes are each subject to a frictional force of 6.0 N, what is the magnitude
of the force exerted on the right cube by the middle cube in this case?
a. 12 N
b. 24 N
c. 36 N
d. none of the above
____ 36. Hector drives a pickup truck horizontally at 15.0 m/s. He is transporting a crate of delicate lead crystal. If the
coefficient of static friction between the crate and the truck bed is 0.400, what is the minimum stopping distance
for the truck so the crate will not slide?
a. 28.7 m
b. 51.0 m
c. 33.6 m
d. 44.4 m
____ 37. A hockey puck moving at 7.0 m/s coasts to a halt in 75 m on a smooth ice surface. What is the coefficient of
friction between the ice and the puck?
a. µ  0.025
b. µ  0.033
c. µ  0.12
d. µ  0.25
____ 38. A 9.0-kg hanging weight is connected by a string over a pulley to a 5.0-kg block sliding on a flat table. If the
coefficient of sliding friction is 0.20, find the tension in the string.
a.
b.
c.
d.
19 N
24 N
32 N
38 N
Free Response:
1. A net force of 9.0N east is used to push a 20.0kg object. What is the acceleration of the object?
(0.45m/s2 East)
2. A net force of 15.0N north is used to pull an object. If the acceleration of the object is 8.0m/s 2
north, what is the mass of the object? (1.9kg)
3. A 16.0kg object is accelerated at a rate of 2.0m/s2 by a net force. What is the magnitude of this
force? (32N)
4. A 12.0kg object is accelerated by a net force of 10.2N east. What is the acceleration of the object?
(0.850m/s2 east)
5. A 925kg car accelerates uniformly from rest to a velocity of 25.0m/s south in 10.0s. What is the
net force acting on the car during this time? (2.31x103N south)
6. A 1.08x103kg car uniformly accelerates from rest for 12.0s. During this time the car travels 132m
north. What is the net force acting on the car? (1.98x103N north)
7. A net force of 6.6N east acts on a 9.0kg object. If this object accelerates uniformly from rest to a
velocity of 3.0m/s east. How far did the object travel and how long did it take? (6.1m and 4.1s)
8. An 11.0kg object is thrown vertically into the air with an applied force of 145N. What is the
initial acceleration of the object? (3.37m/s2)
9. A 12.0kg object is pushed with a horizontal force of 6.0N East across a table. If the force of
friction is 2.0N, what is the acceleration of the object? (0.33m/s2 East)
10. A 15.0kg object is thrown vertically into the air. The initial acceleration of the object is 8.80m/s 2,
what is the applied force? (279N)
11. A 20.0kg object is pulled horizontally along a level floor with a force of 27.0N. If the object is
accelerating at a rate of 0.80m/s2, what is the magnitude of the force of friction? (11N)
12. An object is pulled west along a horizontal frictionless surface with a steady horizontal force of
12.0N. If the object accelerates from rest to a velocity of 4.0m/s while moving 5.0m, what is the
mass of the object? (7.5kg)
13. What is the tension in the cable of an 1.20x103kg elevator that is
a. Accelerating downward at a rate of 1.05m/s2? (1.05x104N)
b. Accelerating upward at a rate of 1.05m/s2? (1.31x104N)
c. moving downward at a constant velocity of 1.10m/s? (1.18x104N)
14. An object that has a mass of 36.0kg is pushed along a horizontal surface with a force of 85.0N. IF
the force of friction is 72.0N, what is the magnitude of the acceleration of the object? (0.361m/s2)
15. As horizontal force of 90.0N is required to push a 75.0kg along a horizontal surface at a constant
speed. What is the magnitude of the force of friction? (90.0N)
16. A 1.0kg object is given a push along a horizontal surface. IF the velocity of the object when it is
released is 0.50m/s west, and the object slides 0.25m before coming to a stop, what is the
magnitude of the force of friction? (0.50N)
17. A 7.0kg object rests on a horizontal frictionless surface. What is the magnitude of the horizontal
force that is required to accelerate it at the rate of 2.3m/s2? (16N)
18. You are traveling in your car at a velocity of 24.0m/s east when you slam on your brakes. The
force of friction on your car tires is 1.80x104N. IF the mass of you and your car is 1.50x10 3kg,
how far do you skid before stopping? (24.0m)
19. A 1.0kg box on a horizontal frictionless surface is accelerated by attaching and hanging a 1.5 kg
mass over a pulley. What is the acceleration of the box? (Remember both boxes are accelerated).
(5.9m/s2)
20. Two masses of 1.5kg and 2.0kg are hung on a vertical frictionless pulley. What is the acceleration
of
a. 1.5kg mass? (1.4m/s2)
b. 2.0kg mass? (-1.4m/s2)
Q1 CP Physics
Answer Section
MULTIPLE CHOICE
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35.
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B
PTS: 1
DIF: 1
TOP: 2.1 Displacement
B
PTS: 1
DIF: 1
TOP: 2.2 Velocity
A
PTS: 1
DIF: 2
TOP: 2.2 Velocity
B
PTS: 1
DIF: 2
TOP: 2.2 Velocity
B
PTS: 1
DIF: 2
TOP: 2.2 Velocity
B
PTS: 1
DIF: 1
TOP: 2.2 Velocity
A
PTS: 1
DIF: 2
TOP: 2.3 Acceleration
B
PTS: 1
DIF: 1
TOP: 2.3 Acceleration
B
PTS: 1
DIF: 1
TOP: 2.3 Acceleration
D
PTS: 1
DIF: 1
TOP: 2.3 Acceleration
A
PTS: 1
DIF: 2
TOP: 2.3 Acceleration
D
PTS: 1
DIF: 2
2.5 One-Dimensional Motion with Constant Acceleration
C
PTS: 1
DIF: 2
2.5 One-Dimensional Motion with Constant Acceleration
B
PTS: 1
DIF: 2
2.5 One-Dimensional Motion with Constant Acceleration
A
PTS: 1
DIF: 2
2.5 One-Dimensional Motion with Constant Acceleration
B
PTS: 1
DIF: 2
TOP: 2.6 Freely-Falling Objects
B
PTS: 1
DIF: 2
TOP: 2.6 Freely-Falling Objects
A
PTS: 1
DIF: 2
TOP: 2.6 Freely-Falling Objects
C
PTS: 1
DIF: 2
TOP: 2.6 Freely-Falling Objects
A
PTS: 1
DIF: 2
TOP: 2.6 Freely-Falling Objects
D
PTS: 1
DIF: 3
TOP: 2.6 Freely-Falling Objects
A
PTS: 1
DIF: 2
TOP: 2.6 Freely-Falling Objects
B
PTS: 1
DIF: 2
TOP: 2.6 Freely-Falling Objects
A
PTS: 1
DIF: 1
TOP: 3.1 Vectors and Their Properties
C
PTS: 1
DIF: 3
TOP: 3.4 Motion in Two Dimensions
A
PTS: 1
DIF: 1
4.1 Forces | 4.2 Newton's First Law | 4.3 Newton's Second Law | 4.4 Newton's Third Law
A
PTS: 1
DIF: 1
4.1 Forces | 4.2 Newton's First Law | 4.3 Newton's Second Law | 4.4 Newton's Third Law
A
PTS: 1
DIF: 3
4.1 Forces | 4.2 Newton's First Law | 4.3 Newton's Second Law | 4.4 Newton's Third Law
D
PTS: 1
DIF: 2
TOP: 4.5 Applications of Newton's Laws
D
PTS: 1
DIF: 3
TOP: 4.5 Applications of Newton's Laws
A
PTS: 1
DIF: 3
TOP: 4.5 Applications of Newton's Laws
B
PTS: 1
DIF: 2
TOP: 4.5 Applications of Newton's Laws
A
PTS: 1
DIF: 3
TOP: 4.6 Forces of Friction
B
PTS: 1
DIF: 3
TOP: 4.6 Forces of Friction
A
PTS: 1
DIF: 3
TOP: 4.6 Forces of Friction
36. ANS: A
37. ANS: B
38. ANS: D
PTS: 1
PTS: 1
PTS: 1
DIF: 3
DIF: 2
DIF: 3
TOP: 4.6 Forces of Friction
TOP: 4.6 Forces of Friction
TOP: 4.6 Forces of Friction