Download During a relay race, runner A runs a certain distance due north and

Unit 1 – 1D Motion
1. During a relay race, runner A runs a certain distance due north and then hands off the
baton to runner B, who runs for the same distance in a direction south of east. The two
displacement vectors A and B can be added together to give a resultant vector R. Which
drawing correctly shows the resultant vector?
A
B
C
D
2. The drawing on below shows a displacement vector A (450.0 m along the -y axis). In
this x, y coordinate system the scalar components are Ax = 0 m and Ay = -450.0 m.
Suppose that the coordinate system is rotated counterclockwise by 35.0°, but the
magnitude (450.0 m) and direction of vector A remain unchanged (see the right drawing).
What are the scalar components, Ax' and Ay', of the vector A in the rotated x', y' coordinate
system?
A Ax' = -450 cos 35o m and Ay' = -450 sin 35o m
B Ax' = +450 cos 35o m and Ay' = -450 sin 35o m
C Ax' = +450 sin 35o m and Ay' = +450 con 35o m
D Ax' = +450 sin 35o m and Ay' = -450 con 35o m
E Ax' = -450 sin 35o m and Ay' = -450 cos 35o m
3. Three runners start at the same place. Shaun runs 4.0 km due east and then runs 1.0
km due west. Mark runs 3.0 km due east. Jeff runs 2.0 km due west and then runs 5.0 km
due east. Which of the following is true concerning the displacement of each runner?
A Shaun's displacement equals Mark's displacement, but Jeff's displacement is
different.
B Mark's displacement equals Jeff's displacement, but Shaun's displacement is
different.
C Shaun, Mark, and Jeff have the same displacements.
D Shaun, Mark, and Jeff have different displacements.
E Shaun's displacement equals Jeff's, but Mark's displacement is different.
4. The average acceleration is zero when __________
A the magnitudes of the initial and final velocities are the same, and the directions of
the initial and final velocities are different.
B both the magnitudes and the directions of the initial and final velocities are the same.
C the magnitude of the final velocity is greater than the magnitude of the initial
velocity, and the direction of the velocity remains constant.
D the initial and the final velocities have different magnitudes and different directions.
5. Which one of the following statements is not true?
A In the absence of air resistance the motion of a baseball dropped from rest from the
top of a building is an example of free-fall.
B In the absence of air resistance the motion of a baseball after being thrown straight
upward from the ground is an example of free-fall.
C The equations of kinematics apply to free-fall motion.
D Near the earth's surface the acceleration due to gravity has the approximate
magnitude of 9.80 m/s2, points downward when the motion is downward, and points
upward when the motion is upward.
E In free-fall motion near the earth's surface the acceleration is the acceleration due to
gravity.
6. The graph that accompanies this problem shows a three-part motion. Rank the
velocities of three parts, A, B, and C, in ascending order (smallest first).
A vC, vA, vB
B vA, vC, vB
C vA, vB, vC
D vC, vB, vA
E vB, vC, vA
7. For the motion described in the graph that accompanies this problem decide whether
the moving object is accelerating, decelerating, or moving at a constant velocity.
A Accelerating
B Moving at a constant velocity
C Decelerating
D There is insufficient information for an answer.
Unit 2 – 2D Motion
8. The drawing shows projectile motion at three points along the trajectory. The speeds
at the points are v1, v2, and v3. Assume there is no air resistance and rank the speeds,
largest to smallest. (Note that the symbol ">" means "greater than.")
A v1 > v3 > v2
B v1 > v2 > v3
C v2 > v3 > v1
D v2 > v1 > v3
E v3 > v2 > v1
9. At a certain point along the path in projectile motion, the projectile has a velocity v
whose scalar components are vx = +30 m/s and vy = +40 m/s. As the projectile moves
along the path, what would be its minimum speed?
A 0 m/s
B 30 m/s
C 40 m/s
D
10. Each drawing shows three points along the path of a projectile, one on its way up,
one at the top, and one on its way down. Which drawing correctly represents the
acceleration a of the projectile at these three points?
A
B
C
D
E
11. Suppose Ball 1 is at a height of 19.6 m when it reaches the top of its trajectory. At
the instant Ball 1 is at the top of its trajectory, Ball 2 is released from rest at the same
height. How much time does it take for either ball to reach the ground? Note that the
vertical component y of the ball's displacement points downward, in the -y direction.
A 2.0 s
B 4.0 s
C 6.0 s
D 1.0 s
E 0.50 s.
12. An object is moving at a constant velocity. All but one of the following could be
true. Which one cannot be true?
A No forces act on the object.
B A single force acts on the object.
C Two forces act simultaneously on the object.
D Three forces act simultaneously on the object.
Unit 3 – Newton’s Laws & Force
13. Which one of the following descriptions violates Newton's first law of motion?
A A child is sitting in the back seat of a car and is not wearing a seat belt. The car is
traveling forward, and the driver suddenly applies the brakes. The child flies forward
against the rear side of the front seat.
B A small suitcase is at the front of the overhead luggage compartment on an airplane.
When the airplane begins its takeoff, the suitcase slides to the rear of the
compartment.
C A glass of water is sitting on a table in the dining car of a train. The train brakes as it
nears the station, and the glass slides forward.
D A rabbit's foot is hanging on a chain from the rearview mirror of a car. As the car
accelerates, the rabbit's foot swings toward the windshield.
14. Two forces act on a moving object that has a mass of 5 kg. One has a magnitude of
12 N and points due south, while the other has a magnitude of 37 N and points due north.
What is the acceleration of the object?
A 5 m/s2 directed south
B 10 m/s2 directed south
C 5 m/s2 directed north
D 10 m/s2 directed north
E 50 m/s2 directed north
15. Which one of the following is true, according to Newton's laws of motion? Ignore
friction.
A A sports utility vehicle (SUV) hits a stationary motorcycle. Since it is stationary, the
motorcycle sustains a greater force than the SUV does.
B A semi-truck crashes all the way through a wall. Since it collapses, the wall sustains
a greater force than the truck does.
C Sam (18 years old) and his sister (9 years old) go ice skating. They push off against
each other and fly apart. Sam flies off with the greater acceleration.
D Two astronauts on a "space walk" are throwing a ball back and forth between each
other. In this game of "catch" the distance between them remains constant.
E None of the above is true, according to the third law.
16. In another solar system a planet has four times the earth's mass and two times the
earth's radius. Your weight on this planet is _______ times your earth-weight. Assume
that the masses of the earth and the other planet are uniformly distributed.
A 1
B 2
C 0.111
D 0.444
E 0.222
17. The apparent weight of a passenger in an elevator is greater than his true weight.
Which one of the following is true?
A The elevator is moving upward with an increasing speed or moving upward with an
decreasing speed.
B The elevator is moving upward with an increasing speed or moving downward with
an increasing speed.
C The elevator is moving upward with a decreasing speed or downward with a
decreasing speed.
D The elevator is moving upward with an increasing speed or moving downward with
a decreasing speed.
E The elevator is moving upward with a decreasing speed or downward with in
increasing speed.
18. The drawings show identical blocks at rest on three different inclines, each block
held in place by static friction. Rank the forces of static friction in the three cases in
ascending order (smallest first).
A B, C, A
B A, C, B
C B, A, C
D A, B, C
E C, A, B
19. The drawings show three identical blocks sliding along horizontal surfaces. Each
block has a different mass, as indicated. The coefficient of kinetic friction in each case is
the same. Which block has the greatest deceleration?
A A
B B
C C
D The deceleration is the same in
each case.
20. A certain object is in equilibrium. Which one of the following statements is not true?
A The object must be at rest.
B The object has a constant velocity.
C The object has no acceleration.
D No net force acts on the object.
21. A certain object is not in equilibrium. Three of the following statements could
possibly be true, and one must be true. Which one of the following must be true?
A Only a single force acts on the object.
B A net force acts on the object.
C Only two perpendicular forces act on the object.
D Only three forces act on the object.
22. The drawing shows a block at rest on an incline. The mass of the block is 8.0 kg.
What is the static frictional force that acts on the block?
A 8*10*cos 22o N
B 8*cos 22o N
C -8*10*cos 22o N
D -8*10*sin 22o N
E There is not enough information to calculate the frictional
force.
Unit 4 – Uniform Circular Motion
23.
Two cars are traveling at the same constant speed v. Car A is
moving along a straight section of the road, while B is
rounding a circular turn. Which statement is true about the
acceleration of the cars?
A The acceleration of both cars is zero, since they are traveling at a constant speed.
B Car A is accelerating, but car B is not accelerating.
C Car A is not accelerating, but car B is accelerating.
D Both cars are accelerating.
24. A small cylinder rests on a circular turntable that is rotating clockwise at a constant
speed. Which set of vectors gives the direction of the velocity v and acceleration a of the
cylinder, and the net force ΣF that acts on it.
A
C
B
D
25. A car is rounding a circular curve of radius r on a banked turn. As the drawing
indicates, there are two forces acting on the car, its weight mg and the normal force FN
exerted on it by the road. Which force, or force component, provides the centripetal force
that keeps the car moving on the circular path?
A The normal force, FN.
B The weight, mg, of the car.
C The vertical component, FN cos θ, of the normal
force.
D The horizontal component, FN sin θ, of the normal
force.
E Both the normal force, FN, and the weight, mg, of the
car.
26. The drawing shows an extreme skier at three locations on a ski run: (A) a straight
section, (B) a circular section, and (C) an airborne phase in which the skier is in free-fall.
At the right of the drawing are four possible directions for the net force that acts on the
skier. What is the direction of the net force at A, B, and C? Assume that there is no
friction or air resistance at any point along the ski run.
A 4, 3, 2
B 3, 1, 3
C 2, 3, 2
D 2, 1, 3
E 2, 1, 1
27. The drawing shows an extreme skier at bottom of a ski jump. At this point the track
is circular with a radius r. Two forces act on the skier, her weight mg and the normal
force FN. Which relation describes how the net force acting on her is related to her mass
m and speed v and to the radius r? Assume that "up" is the positive direction.
A
B
C
D
Unit 5 – Work & Energy
28. The same force F pushes in three different ways on a box moving with a velocity v,
as the drawings show. Rank the work done by the force F in ascending order (smallest
first).
A A, B, C
B A, C, B
C B, A, C
D C, B, A
E C, A, B
29. A force F acts on an object undergoing a displacement s, the force being oriented at
an angle θ with respect to the displacement. Which one of the following correctly
describes ALL of the circumstances under which the work done by the force is zero?
A The force is zero, or the displacement is zero.
B The displacement is zero, or the angle is 90°.
C The force is zero, or the displacement is zero, or the angle is 90°.
D The force is zero, or the angle is 90°.
E The force is zero, or the displacement is zero, or the angle is 180°.
30. Air resistance is a non-conservative force. It always opposes the motion of an object.
An airplane flies from New York to Atlanta and then returns to its point of departure. The
net work done by air resistance during this round trip is
A negative for higher speeds and positive for slower speeds
B negative for slower speeds and positive for higher speeds
C zero
D positive
E negative
31. A stone is thrown with a speed v0 and returns to earth, as the drawing shows. Ignore
friction and air resistance, and consider the initial and final locations of the stone. Which
one of the following correctly describes the change ΔPE in the gravitational potential
energy and the change ΔKE in the kinetic energy of the stone as it moves from its initial
to its final location?
A ΔPE = 0 J and ΔKE = 0 J
B ΔPE is positive and ΔKE is negative
C ΔPE is negative and ΔKE is positive
D ΔPE = 0 J and ΔKE is positive
E ΔPE = 0 J and ΔKE is negative
32. A bicycle rider has a speed of 2 m/s at a height of 5 m above sea level when he
begins coasting down hill. The mass of the rider and his bike is 50 kg. Sea level is the
zero level for measuring gravitational potential energy. Ignoring friction and air
resistance, what is the rider's total mechanical energy when he coasts to a height of 1 m
above sea level?
A 100 J
B 2500 J
C 2600 J
D 40 J
33. A 90.0-kg skydiver falls straight downward with an open parachute through a
vertical height of 300 m. The skydiver's velocity remains constant. What is the work done
by the non-conservative force of air resistance, which is the only non-conservative force
acting?
A -270,000 J
B 0J
C +270,000 J
D Answer is not obtainable, because there is insufficient information about speed.
34. Two identical cars are traveling at the same speed. One is heading due east and the
other due north, as the drawing shows. Which statement is true regarding the kinetic
energies and momenta of the cars?
A They have the same kinetic energies and the same momenta.
B They have the same kinetic energies, but different momenta.
C They have different kinetic energies, but the same momenta.
D They have different kinetic energies and different momenta.
35. A high-jumper, having just cleared the bar, lands on an air mattress and comes to
rest. Had she landed directly on the hard ground, her stopping time would have been
much shorter. Using the impulse-momentum theorem as your guide, determine which one
of the following statements is correct.
A The air mattress exerts a greater impulse, and a greater net average force, on the
high-jumper than does the hard ground.
B The air mattress exerts a greater impulse, but a smaller net average force, on the
high-jumper than does the hard ground.
C The air mattress exerts the same impulse, but a greater net average force, on the
high-jumper than does the hard ground.
D The air mattress exerts the same impulse, but a smaller net average force, on the
high-jumper than does the hard ground.
E The air mattress exerts a smaller impulse, and a smaller net average force, on the
high-jumper than does the hard ground.
36. The drawing illustrates an overhead view of a door and its axis of rotation. The axis
is perpendicular to the screen. There are four forces acting on the door, and they have
the same magnitude. Rank the torque that each force produces, largest to smallest.
A F4, F3, F2, F1
B F3, F2, F1 and F4 (a two-way tie)
C F2, F4, F3, F1
D F1, F4, F3, F2
E F2, F3 and F4 (a two-way tie), F1
38. Two blocks are placed at the ends of a mass-less board. The board is balanced on
a support that serves as an axis of rotation. Which statement best describes the
picture?
A - The bar is at rotational equilibrium.
B - The bar will rotate clockwise.
C - The bar will rotate counter clockwise.
D - Not enough information given to determine what it will do.
39. Two objects undergo an elastic collision. The table shows four possible sets of the
initial and final kinetic energies of the objects. Which is the only set that could occur?
Initial Kinetic Energies (Before Collision) Final Kinetic Energies (After Collision)
Object 1
Object 2
Object 1
Object 2
A
15 J
0J
10 J
9J
B
8J
6J
10 J
4J
C
8J
6J
16 J
-2 J
D
3J
8J
2J
6J
40. A particle is moving along the +x axis, and the graph shows its momentum p as a
function of time t. In each of the four regions a force may, or may not, be applied to
the particle. In which region is the magnitude of the force largest and in which region
is it smallest?
A - B (largest), D (smallest)
B - C (largest), B (smallest)
C - A (largest), D (smallest)
D - C (largest), A (smallest)
E - A (largest), C (smallest)
41. You have two springs. One has a greater spring constant than
the other. You also have two objects, one with a greater mass than
the other. Which object should be attached to which spring, so that
the resulting spring-object system has the greatest possible period
of oscillation?
A The object with the greater mass should be attached to the spring
with the greater spring constant.
B The object with the greater mass should be attached to the spring
with the smaller spring constant.
C The object with the smaller mass should be attached to the spring
with the smaller spring constant.
D The object with the smaller mass should be attached to the spring
with the greater spring constant.
The drawing shows a graph of displacement x versus time t for
simple harmonic motion of an object on a horizontal spring. Which
one of the following answers correctly gives the magnitude v of the
velocity and the magnitude a of the acceleration at points A and B
in the graph?
A vA = maximum, aA = maximum,
vB = 0 m/s, aB = 0 m/s2
B vA = maximum, aA = 0 m/s2, vB = 0 m/s,
aB = maximum
C vA = 0 m/s, aA = 0 m/s2, vB = maximum,
aB = maximum
D vA = 0 m/s, aA = maximum,
vB = maximum, aB = 0 m/s2
E vA = maximum, aA = maximum,
vB = 0 m/s, aB = maximum
Which one of the following graphs correctly represents the restoring
force F of an ideal spring as a function of the displacement x of the
spring from its unstrained length?
A
B
C
The kinetic energy of an object attached to a horizontal ideal spring
is denoted by KE and the elastic potential energy by PE. For the
simple harmonic motion of this object the maximum kinetic energy
and the maximum elastic potential energy during an oscillation cycle
are KEmax and PEmax, respectively. In the absence of friction, air
resistance, and any other nonconservative forces, which of the
following equations applies to the object-spring system?
A. KE + PE = constant
B. KEmax = PEmax
A A, but not B
B B, but not A
C A and B
D Neither A, nor B
The drawing shows an object attached to an ideal spring, which is
hanging from the ceiling. The unstrained length of the spring is
indicated. For purposes of measuring the height h that determines
the gravitational potential energy, the floor is taken as the position
where h = 0 m. The equilibrium position at which the object hangs
stationary is identified as position 2. The object is set into vertical
simple harmonic motion between positions 1 and 3. Identify the
positions where the kinetic energy KE, the elastic potential energy
EPE, and the gravitational potential energy GPE each have their
maximum values during an oscillation cycle.
A KE has a maximum value at position 2.
EPE has a maximum value at position 1.
GPE has a maximum value at position 3.
B KE has a maximum value at position 1.
EPE has a maximum value at position 3.
GPE has a maximum value at position 2.
C KE has a maximum value at position 3.
EPE has a maximum value at position 2.
GPE has a maximum value at position 1.
D KE has a maximum value at position 1.
EPE has a maximum value at position 2.
GPE has a maximum value at position 3.
E KE has a maximum value at position 2.
EPE has a maximum value at position 3.
GPE has a maximum value at position 1.
Five simple pendulums are shown in the drawings. The lengths of
the pendulums are drawn to scale, and the masses are either m or
2m, as shown. Which one has the smallest angular frequency of
oscillation?
A
B
C
D
E