Download Physics Fall Semester Final Answer Section

Physics Fall Semester Final
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. The SI base unit used to measure mass is the
a. meter.
b. second.
c. kilogram.
d. liter.
____
2. A hypothesis is
a. the long side of a right triangle.
b. an educated guess that has yet to be proven by experiment.
c. close agreement by competent observers of observations of the same phenomena.
d. a guess that has been tested over and over again and always found to be true.
e. a synthesis of a large collection of information that includes guesses.
____
3. Which of the following is the equation for average velocity?
a.
c. v
= xt
b.
d.
____
4. Which of the following situations represents a negative displacement? (Assume positive position is measured
vertically upward along a y-axis.)
a. A cat stands on a tree limb.
b. A cat jumps from the ground onto a tree limb.
c. A cat jumps from a lower tree limb to a higher one.
d. A cat jumps from a tree limb to the ground.
____
5. Which of the following units is the SI unit of velocity?
a. meter
c. meter per second
b. metersecond
d. second per meter
____
6. When a car’s velocity is negative and its acceleration is negative, what is happening to the car’s motion?
a. The car slows down.
c. The car travels at constant speed.
b. The car speeds up.
d. The car remains at rest.
____
7. What does the graph above illustrate about acceleration?
a. The acceleration varies.
b. The acceleration is zero.
c. The acceleration is constant.
d. The acceleration increases then becomes constant.
____
8. In the graph above, how does the acceleration at A compare with the acceleration at B?
a. The acceleration at A is positive and less than the acceleration at B.
b. The acceleration at B is positive and less than the acceleration at A.
c. The accelerations at A and B are each zero.
d. The accelerations at A and B cannot be determined.
____
9. The graph above describes the motion of a ball. At what point is the speed of the ball equal to its speed at B?
a. A
c. D
b. C
d. none of the above
____ 10. Which of the following statements applies to the motion of a ball rising and then falling in free fall?
I. The ball has constant acceleration as it moves upward.
II. The ball has constant acceleration at the top of its path.
III. The ball has constant acceleration as it moves downward.
a. I only
b. III only
c. I and III
d. I, II, and III
____ 11. Which would fall with greater acceleration in a vacuum—a leaf or a stone?
a. the leaf
b. the stone
c. They would accelerate at the same rate.
d. It is difficult to determine without more information.
____ 12. A vector is a quantity that has
a. magnitude and time.
b. time and direction.
c. magnitude and direction.
____ 13. In the absence of air friction, the horizontal component of a projectile's velocity doesn't change as the
projectile moves.
a. Sometimes true
b. Always true
c. Always false
____ 14. At the instant a ball is thrown horizontally with a large force, an identical ball is dropped from the same
height. Which ball hits the ground first?
a. Neither. They both hit the ground at the same time.
b. The dropped ball
c. The horizontally thrown ball
____ 15. A ball thrown in the air will never go as far as physics ideally would predict because
a. one can never throw the ball fast enough.
b. gravity is acting.
c. air friction slows the ball.
d. ideally the ball would never land.
e. all of the above
____ 16. At what part of a path does a projectile have minimum speed?
a. When it returns to the ground
b. Halfway to the top
c. At the top of its path
d. When it is thrown
e. There's not enough information to say.
____ 17. A cannonball is launched from the ground at an angle of 30 degrees above the horizontal and a speed of 30
m/s. Ideally (no air resistance) the ball will land on the ground with a speed of
a. 0 m/s.
b. 20 m/s.
c. 30 m/s.
d. 40 m/s.
e. There is not enough information to say.
____ 18. An object is dropped and falls freely to the ground with an acceleration of g. If it is thrown upward at an angle
instead, its acceleration would be
a. 0.
b. larger than g.
c. g upward.
d. g downward.
e. none of the above
____ 19. An airplane flying into a head wind loses ground speed, and an airplane flying with the wind gains ground
speed. If an airplane flies at right angles to the wind, then ground speed is
a. more.
b. unchanged.
c. less.
____ 20. In Chapter 2, you learned about "hang time," the time a jumper's feet are off the ground in a vertical jump. If
the jumper runs horizontally and has the same vertical component of takeoff velocity, hang time will be
a. no different.
b. decreased.
c. increased.
____ 21. Suppose a small plane can fly at 170 km/h relative to the surrounding air. Suppose also that there is a 60 km/h
tailwind. How fast does the plane's shadow move across the ground?
a. 5 km/h
b. 60 km/h
c. 110 km/h
d. 170 km/h
e. 230 km/h
____ 22. A cannon with a barrel velocity of 140 m/s launches a cannonball horizontally from a tower. Neglecting air
resistance, how far vertically will the cannonball have fallen after 4 seconds?
a. 80 m
b. 140 m
c. 560 m
d. 2240 m
e. none of the above
____ 23. The law of inertia applies to
a. objects at rest.
b. moving objects.
c. both moving and nonmoving objects.
____ 24. An object following a straight-line path at constant speed
a. has no forces acting on it.
b. has a net force acting on it in the direction of motion.
c. has zero acceleration.
d. must be moving in a vacuum.
e. none of the above
____ 25. The mass of a lamb that weighs 110 N is about
a. 1 kg.
b. 11 kg.
c. 110 kg.
d. 1100 kg.
e. none of the above
____ 26. The acceleration produced by a net force on an object is
a. inversely proportional to the mass of the object.
b. directly proportional to the magnitude of the net force.
c. in the same direction as the net force.
d. all of the above
e. none of the above
____ 27. For the winter, a duck flies 10.0 m/s due south against a gust of wind with a speed of 2.5 m/s. What is the
resultant velocity of the duck?
a. 12.5 m/s south
c. 7.5 m/s south
b. –12.5 m/s south
d. –7.5 m/s south
____ 28. An ant on a picnic table travels 3.0  10 cm eastward, then 25 cm northward, and finally 15 cm westward.
What is the magnitude of the ant’s displacement relative to its original position?
a. 70 cm
c. 52 cm
b. 57 cm
d. 29 cm
____ 29. How many displacement vectors shown in the figure above have horizontal components?
a. 2
c. 4
b. 3
d. 5
____ 30. In the figure above, which diagram represents the vector addition C = A + B?
a. I
c. III
b. II
d. IV
____ 31. In the figure above, which diagram represents the vector subtraction C = A–B?
a. I
c. III
b. II
d. IV
____ 32. Identify the following quantities as scalar or vector: the mass of an object, the number of leaves on a tree,
wind velocity.
a. vector, scalar, scalar
c. scalar, vector, scalar
b. scalar, scalar, vector
d. vector, scalar, vector
____ 33. A force of 3 N accelerates a mass of 3 kg at the rate of 1 m/s2. The acceleration of a mass of 6 kg acted upon
by a force of 6 N is
a. twice as much.
b. half as much.
c. the same.
d. none of the above
____ 34. A push on a 1-kilogram brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kilogram
brick, one would have to push
a. with 100 times as much force.
b. with 10 times as much force.
c. with just as much force.
d. with 1 the amount of force.
10
e. none of the above
____ 35. A toybox is dragged without acceleration in a straight-line path across a level surface by a force of 15 N.
What is the frictional force between the toybox and the surface?
a. 15 N
b. Need more information to say.
c. Less than 15 N
d. More than 15 N
____ 36. Aunt Minnie throws a rock downward, and air resistance is negligible. Compared to a rock that is dropped,
the acceleration of the rock after it is thrown is
a. less.
b. the same.
c. more.
____ 37. If you pull horizontally on a desk with a force of 150 N and the desk doesn't move, the friction force must be
150 N. Now if you pull with 250 N so the desk slides at constant velocity, the friction force is
a. more than 150 N but less than 250 N.
b. 250 N.
c. more than 250.
____ 38. Suppose a cart is being moved by a force. If suddenly a load is dumped into the cart so that the cart's mass
doubles, what happens to the cart's acceleration?
a. It quarters.
b. It halves.
c. It stays the same.
d. It doubles.
e. It quadruples.
____ 39. Which of the following is the cause of an acceleration?
a. speed
c. force
b. inertia
d. velocity
____ 40. A newton is equivalent to which of the following quantities?
a. kg
c. kgm/s
b. kgm/s
d. kg(m/s)
____ 41. A sportscar has a mass of 1500 kg and accelerates at 5 meters per second squared. What is the magnitude of
the force acting on the sportscar?
a. 300 N.
b. 1500 N.
c. 2250 N.
d. 7500 N.
e. none of the above
____ 42. A free-body diagram of a ball falling in the presence of air resistance would show
a. only a downward arrow to represent the force of air resistance.
b. only a downward arrow to represent the force due to gravity.
c. a downward arrow to represent the force due to gravity and an upward arrow to represent
the force of air resistance.
d. an upward arrow to represent the force due to gravity and a downward arrow to represent
the force of air resistance.
____ 43. Which of the following is the tendency of an object to maintain its state of motion?
a. acceleration
c. force
b. inertia
d. velocity
____ 44. Which statement about the acceleration of an object is correct?
a. The acceleration of an object is directly proportional to the net external force acting on the
object and inversely proportional to the mass of the object.
b. The acceleration of an object is directly proportional to the net external force acting on the
object and directly proportional to the mass of the object.
c. The acceleration of an object is inversely proportional to the net external force acting on
the object and inversely proportional to the mass of the object.
d. The acceleration of an object is inversely proportional to the net external force acting on
the object and directly proportional to the mass of the object.
____ 45. A net force of 6.8 N accelerates a 31 kg scooter across a level parking lot. What is the magnitude of the
scooter’s acceleration?
a. 0.22 m/s
c. 3.2 m/s
b. 0.69 m/s
d. 4.6 m/s
____ 46. Whenever an object exerts a force on another object, the second object exerts a force of the same magnitude,
but in the opposite direction to that of the first object.
a. Sometimes true
b. Always true
c. Always false
____ 47. A player hits a ball with a bat. The action force is the impact of the bat against the ball. What is the reaction to
this force?
a. The force of the ball against the bat
b. The weight of the ball
c. Air resistance on the ball
d. The grip of the player's hand against the bat
e. none of the above
____ 48. A sled weighing 1.0 10 N is held in place on a frictionless 20.0 slope by a rope attached to a stake at the
top. The rope is parallel to the slope. What is the normal force of the slope acting on the sled?
a. 94 N
c. 37 N
b. 47 N
d. 34 N
____ 49. You drive past a farm, and you see a cow pulling a plow to till a field. You have just learned about Newton’s
third law, and you wonder how the cow is able to move forward if the plow is exerting an equal and opposite
force on the cow. Which of the following explains the movement of the cow and plow?
a. The force exerted by the cow on the plow is equal to the force that the cow exerts on the
ground to move forward.
b. The force exerted by the cow on the plow is larger than the force that the cow exerts on the
ground to move forward.
c. The force exerted by the cow on the plow is smaller than the force that the cow exerts on
the ground to move forward.
d. More information is needed to answer this question.
____ 50. What are the units of the coefficient of friction?
a. N
c. N
b. 1/N
d. The coefficient of friction has no units.
____ 51. Compared to a sports car moving at 30 miles per hour, the same sports car moving at
a. twice as much momentum.
b. four times as much momentum.
c. the same momentum.
miles per hour has
____ 52. Suppose a girl is standing on a pond where there is no friction between her feet and the ice. In order to get off
the ice, she can
a. bend over touching the ice in front of her and then bring her feet to her hands.
b. walk very slowly on tiptoe.
c. get on her hands and knees and crawl off the ice.
d. throw something in the direction opposite to the way she wants to go.
e. all of the above will work
____ 53. A cannon fires a cannonball. The speed of the cannonball will be the same as the speed of the recoiling
cannon
a. if the mass of the cannonball equals the mass of the cannon.
b. because momentum is conserved.
c. because velocity is conserved.
d. because both velocity and momentum are conserved.
e. none of the above
____ 54. A cannonball shot from a long-barrel cannon travels faster than one shot from a short-barrel cannon because
the cannonball receives a greater
a. force.
b. impulse.
c. both A and B
d. neither A nor B
____ 55. A ball is moving at 6.0 m/s and has a momentum of 24.0 kg·m/s. What is the ball's mass?
a. 0.3 kg
b. 4.0 kg
c. 24.0 kg
d. 144.0 kg
e. none of the above
____ 56. A 5.0-kg chunk of putty moving at 10.0 m/s collides with and sticks to a 7.0-kg bowling ball that is initially at
rest. The bowling ball with its putty passenger will then be set in motion with a momentum of
a. 0 kg·m/s.
b. 2.0 kg·m/s.
c. 15.0 kg·m/s.
d. 50.0 kg·m/s.
e. more than 50.0 kg·m/s.
____ 57. A billiard ball collides with a stationary identical billiard ball in an elastic head-on collision. After the
collision, which of the following is true of the first ball?
a. It maintains its initial velocity.
c. It comes to rest.
b. It has one-half its initial velocity.
d. It moves in the opposite direction.
____ 58. Two skaters stand facing each other. One skater’s mass is 60 kg, and the other’s mass is 72 kg. If the skaters
push away from each other without spinning,
a. the lighter skater has less momentum.
b. their momenta are equal but opposite.
c. their total momentum doubles.
d. their total momentum decreases.
____ 59. In a two-body collision,
a. momentum is always conserved.
b. kinetic energy is always conserved.
c. neither momentum nor kinetic energy is conserved.
d. both momentum and kinetic energy are always conserved.
____ 60. A roller coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. The momentum of the roller
coaster
a.
b.
c.
d.
is greater up the hill than down the hill.
is greater down the hill than up the hill.
remains the same throughout the ride.
is zero throughout the ride.
____ 61. A 20 kg shopping cart moving at a velocity of 0.5 m/s collides with a store wall and stops. The momentum of
the shopping cart
a. increases.
c. remains the same.
b. decreases.
d. is conserved.
____ 62. A soccer ball collides with another soccer ball at rest. The total momentum of the balls
a. is zero.
c. remains constant.
b. increases.
d. decreases.
Physics Fall Semester Final
Answer Section
MULTIPLE CHOICE
1. ANS: C
PTS: 1
DIF:
2. ANS: B
PTS: 1
DIF:
KEY: hypothesis | scientific method
MSC:
3. ANS: A
PTS: 1
DIF:
4. ANS: D
PTS: 1
DIF:
5. ANS: C
PTS: 1
DIF:
6. ANS: B
PTS: 1
DIF:
7. ANS: A
PTS: 1
DIF:
8. ANS: C
PTS: 1
DIF:
9. ANS: C
PTS: 1
DIF:
10. ANS: D
PTS: 1
DIF:
11. ANS: C
PTS: 1
DIF:
12. ANS: C
PTS: 1
DIF:
KEY: vector | magnitude
MSC:
13. ANS: B
PTS: 1
DIF:
STA: 12.D
KEY: friction | projectile
14. ANS: A
PTS: 1
DIF:
OBJ: 5.5 Projectiles Launched Horizontally
KEY: projectile | gravity
MSC:
15. ANS: C
PTS: 1
DIF:
STA: 12.D
KEY: friction | projectile
16. ANS: C
PTS: 1
DIF:
STA: 12.D
KEY: projectile | speed
17. ANS: C
PTS: 1
DIF:
STA: 12.D
KEY: projectile | resistance
18. ANS: D
PTS: 1
DIF:
STA: 12.D
KEY: acceleration | gravity
19. ANS: A
PTS: 1
DIF:
KEY: speed | resistance
MSC:
20. ANS: A
PTS: 1
DIF:
STA: 12.D
KEY: hang time | vector
21. ANS: E
PTS: 1
DIF:
KEY: vector
MSC: application
22. ANS: A
PTS: 1
DIF:
STA: 12.D
KEY: projectile | velocity
23. ANS: C
PTS: 1
DIF:
STA: 12.D.4.a
KEY: inertia | moving
24. ANS: C
PTS: 1
DIF:
STA: 12.D.4.a
KEY: speed | acceleration
25. ANS: B
PTS: 1
DIF:
KEY: mass | newtons
MSC:
26. ANS: D
PTS: 1
DIF:
I
L1
knowledge
I
I
I
II
I
II
II
I
I
L1
knowledge
L2
OBJ: 1-2.1
OBJ: 1.3 Scientific Methods
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
2-1.1
2-1.1
2-1.1
2-2.1
2-2.2
2-2.2
2-2.2
2-3.1
2-3.3
5.1 Vector and Scalar Quantities
OBJ: 5.4 Projectile Motion
MSC: comprehension
L2
STA:
comprehension
L2
OBJ:
MSC:
L2
OBJ:
MSC:
L2
OBJ:
MSC:
L2
OBJ:
MSC:
L2
OBJ:
analysis
L2
OBJ:
MSC:
L2
OBJ:
12.D
L2
5.4 Projectile Motion
application
3.4 Newton's Law of Inertia
comprehension
3.4 Newton's Law of Inertia
comprehension
3.5 Mass-A Measure of Inertia
L2
L2
L2
application
L2
OBJ:
MSC:
OBJ:
MSC:
OBJ:
MSC:
OBJ:
5.4 Projectile Motion
comprehension
5.4 Projectile Motion
comprehension
5.4 Projectile Motion
application
5.4 Projectile Motion
analysis
5.2 Velocity Vectors
5.4 Projectile Motion
application
5.2 Velocity Vectors
OBJ: 6.1 Force Causes Acceleration
STA: 12.D
KEY: acceleration | force
27. ANS: C
Given
v = 10.0 m/s south
v = 2.5 m/s north
MSC: comprehension
Solution
vR
PTS: 1
DIF: IIIA
28. ANS: D
Given
x = 3.0 10 cm
y = 25 cm
x = –15 cm
OBJ: 3-1.2
Solution
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
PTS:
ANS:
ANS:
ANS:
ANS:
ANS:
OBJ:
KEY:
ANS:
OBJ:
KEY:
ANS:
STA:
ANS:
KEY:
ANS:
STA:
ANS:
OBJ:
KEY:
1
DIF: IIIA
OBJ: 3-2.2
C
PTS: 1
DIF: I
OBJ:
B
PTS: 1
DIF: I
OBJ:
D
PTS: 1
DIF: I
OBJ:
B
PTS: 1
DIF: II
OBJ:
C
PTS: 1
DIF: L2
6.3 Newton's Second Law of Motion
STA:
acceleration | mass |force
MSC: application
B
PTS: 1
DIF: L2
6.3 Newton's Second Law of Motion
STA:
acceleration | force
MSC: application
A
PTS: 1
DIF: L2
OBJ:
12.D.4.a
KEY: force | friction
MSC:
B
PTS: 1
DIF: L2
OBJ:
acceleration | gravity
MSC: comprehension
B
PTS: 1
DIF: L2
OBJ:
12.D.4.a
KEY: force | friction | velocity
MSC:
B
PTS: 1
DIF: L2
6.3 Newton's Second Law of Motion
STA:
force | mass MSC: application
3-2.3
3-1.2
3-1.2
3-1.1
12.D.4.a
12.D.4.a
6.4 Friction
application
6.6 Free Fall Explained
6.4 Friction
application
12.D.4.a
39. ANS: C
PTS: 1
DIF:
40. ANS: C
PTS: 1
DIF:
41. ANS: D
PTS: 1
DIF:
OBJ: 6.3 Newton's Second Law of Motion
KEY: mass | acceleration
MSC:
42. ANS: C
PTS: 1
DIF:
43. ANS: B
PTS: 1
DIF:
44. ANS: A
PTS: 1
DIF:
45. ANS: A
I
I
L2
OBJ: 4-1.1
OBJ: 4-1.1
STA: 12.D.4.a
application
II
I
I
OBJ: 4-1.2
OBJ: 4-2.1
OBJ: 4-3.1
Given
F
= 6.8 N
m = 31 kg
Solution
PTS:
46. ANS:
KEY:
47. ANS:
STA:
48. ANS:
1
DIF: IIIA
OBJ: 4-3.2
B
PTS: 1
DIF: L1
force | opposite | magnitude
MSC: knowledge
A
PTS: 1
DIF: L2
12.D.4.a
KEY: action | force | reaction
A
OBJ: 7.2 Newton's Third Law
OBJ: 7.3 Identifying Action and Reaction
MSC: comprehension
Given
F = 1.0  10 N
 = 20.0
Solution
PTS:
49. ANS:
STA:
50. ANS:
51. ANS:
STA:
52. ANS:
STA:
53. ANS:
STA:
54. ANS:
STA:
1
C
12.D
D
A
12.D
D
12.D
A
12.D
B
12.D
DIF:
PTS:
KEY:
PTS:
PTS:
KEY:
PTS:
KEY:
PTS:
KEY:
PTS:
KEY:
IIIA
OBJ:
1
DIF:
Newton's third law
1
DIF:
1
DIF:
momentum | mass
1
DIF:
opposite | force
1
DIF:
speed | cannon | mass
1
DIF:
impulse | cannon
4-4.2
L3
I
L2
L2
L2
L2
OBJ:
MSC:
OBJ:
OBJ:
MSC:
OBJ:
MSC:
OBJ:
MSC:
OBJ:
MSC:
7.6 The Horse-Cart Problem
application
4-4.4
8.1 Momentum
comprehension
8.4 Conservation of Momentum
comprehension
8.4 Conservation of Momentum
comprehension
8.2 Impulse Changes Momentum
comprehension
55. ANS:
STA:
56. ANS:
STA:
57. ANS:
58. ANS:
59. ANS:
60. ANS:
61. ANS:
62. ANS:
B
12.D
D
12.D
C
B
A
B
B
C
PTS:
KEY:
PTS:
KEY:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
DIF: L2
mass | momentum
1
DIF: L2
rest | motion | momentum
1
DIF: I
1
DIF: II
1
DIF: I
1
DIF: I
1
DIF: II
1
DIF: I
OBJ:
MSC:
OBJ:
MSC:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
8.1 Momentum
application
8.5 Collisions
application
6-3.3
6-2.2
6-2.3
6-1.2
6-2.1
6-2.2