Name: ________________________ Class: ___________________ Date: __________
ID: A
Exam 2--PHYS 101--07F
Multiple Choice
Identify the choice that best completes the statement or answers the question.
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1. You are in a car traveling 30 m/s towards the West, which we will assume is the negative direction. You
observe a car, across the median, driving 40 m/s towards the East. What is the relative velocity of the car that
you observe with respect to your car (i.e. what is your perceived velocity of the car)?
a. -70 m/s
c. 10 m/s
b. 70 m/s
d. -10 m/s
2. A brick is thrown from the top of a building at an angle of 30° to the horizontal and with an initial speed of 3
m/s. If the brick is in flight for 2.0 s, how tall is the building?
a. 20 m
c. 30 m
b. 100 m
d. 6 m
3. While exploring a cave a spelunker starts at the entrance and moves the following distances: 50.0 m east,
10.0 m at an angle 30.0° south of east, and 100. m north. What is the magnitude of his resultant
displacement?
a. 112 m
c. 120 m
b. 160 m
d. 153 m
4. From the same height and at the same time, one ball is dropped and another ball is fired horizontally. Which
one will hit the ground first?
a. the fired ball
c. it depends on the velocity of the fired
ball
b. the dropped ball
d. both
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Name: ________________________
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ID: A
5. A certain vector has a y-component which is larger than its x-component; both the x- and y-components are
positive and nonzero. Which of these is a possible angle for the vector with respect to the x-axis?
a. 30°
c. 90°
b. 45°
d. 60°
6. A cart is being pulled by a constant force. A cannon in the cart fires directly overhead. Where does the
cannonball fall?
a. in the cart
c. in front of the cart
b. behind the cart
d. not enough information
7. Vector ä
A lies in the x-y plane. At what angle, from the +x axis, will the vector ä
A have negative x- and
y-components?
a. 210°
c. 120°
b. 290°
d. 30°
8. This figure shows the vectors A and B. What is the resultant vector of A-B?
a.
c.
b.
d.
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Name: ________________________
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ID: A
9. Two blocks are fastened to the ceiling of an elevator as in this figure. The elevator accelerates upward at an
acceleration of 5.0 m/s 2. What is the tension in the upper rope?
a. 148 N
d. 98 N
b. 50 N
e. 196 N
c. 296 N
____ 10. A block of mass m rests on the floor of an elevator that is falling downward at -9.8 m/s 2 (it is in freefall).
What is the relationship between the force due to gravity (mg) and the normal force (N) on the block?
a. N=mg
d. N=0
b. N<mg
e. depends on the speed of the elevator
c. N>mg
____ 11. The normal force on an object is always:
a. in the upward direction
d. abnormally large
b. equal to the gravitational force
e. perpendicular to the surface on which the
object sits
c. opposite the direction of the object’s
motion
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Name: ________________________
ID: A
____ 12. In this figure, the block has a mass of 5 kg and sits on an incline plane with an angle
θ=20°. The block is stationary. What is the minimum coefficient of static friction?
a. 0.4
d. 0.6
b. 1.2
e. 2.5
c. 0.2
____ 13. A cart is on a horizontal frictionless table. Once the cart has been pushed and released, what will happen to
it?
a. it will immediately come to a stop
c. it will gradually slow down
b. it will continue at constant velocity
d. it will continue at constant acceleration
____ 14. A mass of 1 kg is on the planet Mars. The radius of the planet Mars is 3.4x10 6 m, and its mass is 6.4x1023 kg.
What acceleration due to gravity does the mass feel on this planet? (The Gravitational constant is 6.67x10 -11
m3/(kg s2).
a.
b.
9.8 m/s2
3.7 m/s2
c.
d.
4
4.5 m/s2
1.6 m/s2
Name: ________________________
ID: A
____ 15. A mass of 10.0 kg rests on a horizontal table. The coefficient of static friction between the table and the
mass is 0.40. What minimum horizontal force is required to push the block?
a. 39 N
c. 25 N
b. -33 N
d. 4.0 N
____ 16. We step on the accelerator of our Subaru providing a force F on the car for a time of 10 seconds and speeding
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it up to a final speed of 60 miles/hour. If the applied force were 2 F, what would be the final speed after 20
seconds?
a. 90 miles/hour
c. 60 miles/hour
b. 30 miles/hour
d. 120 miles/hour
____ 17. An elevator goes upward at a constant acceleration. What is the relationship between the weight of the
object (W) and the normal force on the block (N)?
a. W=N
c. W>N
b. W<N
d. not enough information
____ 18. A force of 10 N at an angle of 30° is applied to a wooden block. This force causes the block to move 1
meter. What is the work done by the force
a. 5 J
c. 10 J
b. 9 J
d. -10 J
____ 19. A 16 kg dog runs at 2 m/s. What speed must a 4 kg cat have in order to thave the same kinetic energy as the
dog?
a. 3 m/s
c. 16 m/s
b. 4 m/s
d. 8 m/s
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Name: ________________________
ID: A
____ 20. In this figure, the bead has a mass of 1 kg and is at rest at point A. It goes down the slope. What is its
velocity at point C?
a.
b.
7.67 m/s
49.0 m/s
c.
d.
98.0 m/s
9.90 m/s
____ 21.
In this figure, the spring has a spring constant of 1000 N/m. The hand compresses the block-spring system to
the left by 50 cm. What is the force, ä
F , exerted on the block by the spring?
a. 500 N
d. 50,000 N
b. 2000 N
e. -500 N
c. -5,000 N
____ 22. Two paths lead to the top of a big hill. One is steep and direct while the other is twice as long but less steep.
How much more potential energy would you gain if you took the longer path?
a. the same
d. one-half as much
b. you gain no potential energy
e. four times as much
c. twice as much
____ 23. A car starts from rest and accelerates to 50 miles per hour (mph). Later it gets on the highway and
accelerates to 100 mph. Which takes more energy: accelerating from 0⇒50 mph or 50⇒100 mph?
c. both the same
a. 0⇒50 mph
b. 50⇒100 mph
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Name: ________________________
ID: A
____ 24.
In this figure, the spring has a spring constant of 1000 N/m. The hand compresses the block-spring system to
the left by 50 cm. What is the elastic potential energy stored in the spring?
a. 125,000 J
d. 500 J
b. 13 J
e. 125 J
c. 250 J
____ 25. The correct answer to this test is “A.” Bubble “A” for this question on your scantron.
a. A
c. C
b. B
d. D
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ID: A
Exam 2--PHYS 101--07F
Answer Section
MULTIPLE CHOICE
1. ANS: B
CT
PTS: 1
2. ANS: A
HW
PTS: 1
3. ANS: A
HW
PTS: 1
4. ANS: D
CT
PTS: 1
5. ANS: D
CT
PTS: 1
6. ANS: B
CT
PTS: 1
7. ANS: A
HW
PTS: 1
8. ANS: A
HW
PTS: 1
9. ANS: C
HW
PTS: 1
10. ANS: D
CT
PTS: 1
1
ID: A
11. ANS: E
CT
PTS: 1
12. ANS: A
HW,diff
PTS: 1
13. ANS: B
CT
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CT
1
B
A
C
B
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ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
1
B
B
A
A
A
B
E
A
PTS: 1
PTS: 1
PTS: 1
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
2