True-false questions are worth 2 points each, three-choice multiple
choice questions are worth 3 points each, five-choice multiple choice
questions are worth 6 points each. The maximum possible score is 98.
The exam period was 90 minutes. The mean score was 71.9; the median was
74. Click here to see page1
page2 of the formula sheet that came
with the exam.
A 2-kg disk and a 4-kg disk slide on a horizontal frictionless
surface. The 2-kg disk is initially traveling in the positive
x-direction at 7 m/s, the 4-kg disk is initially traveling in the
positive y-direction at 5 m/s. The disks collide and stick together as
shown in the figure below.
What is the final speed | v | of the two disks after the collision?
(a) | v | = 4.1 m/s
(b) | v | = 8.6 m/s
(c) | v | = 12 m/s
(a) θ = 37°
(b) θ = 55°
(c) θ = 64°
A massless 100-cm stick has a 2-kg ball on one end, and an 8-kg ball
on the other as shown below.
Where is the center of mass located for this system?
(a) 50 cm to the right of the 2-kg ball
(b) 70 cm to the right of the 2-kg ball
(c) 80 cm to the right of the 2-kg ball
(a) I = 2.5 kg m2
(b) I = 5.0 kg m2
(c) I = 10 kg m2
A uniform one-meter bar has a mass of 10 kg. One end of the bar is
hinged to a building, and the other end is suspended by a cable that
makes an angle of 45° above the horizontal as shown in the picture.
What is the tension T in the cable?
(a) |T| = 69 N
(b) |T| = 98 N
(c) |T| = 113 N
(d) |T| = 129 N
(e) |T| = 132 N
(a) | Fy | = 0
(b) | Fy | = 26 N
(c) | Fy | = 49 N
(d) | Fy | = 72 N
(e) | Fy | = 98 N
A three-meter plank has a mass of 15 kg and is supported by two
saw-horses as shown below. The first saw-horse is at the right end, and
the second saw-horse is two meters to the left of the first.
What is the force that the left saw-horse provides to support the
(a) F2 = 73.5 N
(b) F2 = 110 N
(c) F2 = 147 N
(a) F1 = 37 N
(b) F1 = 73.5 N
(c) F1 = 147 N
(a) d = 2.35 m
(b) d = 2.5 m
(c) d = 2.75 m
(a) F2 = 73.5 N
(b) F2 = 123 N
(c) F2 = 245 N
A 4-kg block, starting at rest, is moved a distance d = 3 meters across
a horizontal frictionless floor by a force F at an angle θ
= 31° with respect to the floor, as shown in the figure. The force
does work in the amount of 44 J on the block during the displacement.
What is the magnitude of the force?
(a) 7 N
(b) 15 N
(c) 17 N
(a) v = 1.5 m/s
(b) v = 2.3 m/s
(c) v = 3.8 m/s
(d) v = 4.7 m/s
(e) v = 5.1 m/s
A skier starts at rest from the top of a hill at height h
above ground. The skier glides down the hill to point A and continues
up a second hill 9 meters high and back down the other side. Her entire
trip up to point C is frictionless. After point C, there is friction
between her skis and the ground. She comes to a complete stop 53 meters
after point C, at point D.
Of the three listed below which is the smallest value of the height
h so that the skier reaches point C?
(a) 5 m
(b) 10 m
(c) 15 m
(a) v = 4 m/s
(b) v = 13 m/s
(c) v = 21 m/s
(d) v = 35 m/s
(e) v = 44 m/s
A 2-kg block is released from rest and slides down an incline with
angle θ = 41°. The coefficient of kinetic friction between
the block and the incline is 0.27. The block goes down a distance D
along the incline where it hits a wall and rebounds. Just before it
hits the wall, the block has a speed v = 3 m/s.
What is the distance D traveled by the block on the incline on its
(a) 1 m
(b) 2 m
(c) 3 m
(d) 4 m
(e) 5 m
(a) 3 J
(b) 5 J
(c) 9 J
(d) 11 J
(e) 13 J
(a) 100 N
(b) 200 N
(c) 300 N
Two 5-kg blocks are connected by a taught, massless string that runs
over a massless pulley. The first block is on a horizontal frictionless
surface and the right block slides down a frictionless incline. The
blocks start from rest with the right block at the top of a frictionless
incline that has a height of 0.8 m, as shown.
Calculate the speed of the right-side 5-kg block after the it reaches
the bottom of the incline, assuming that the left-side 5-kg block does
not hit the pulley.
(a) v = 2.8 m/s
(b) v = 4.0 m/s
(c) v = 4.6 m/s
(a) v = 1.1 m/s
(b) v = 2.1 m/s
(c) v = 2.3 m/s
(d) v = 2.7 m/s
(e) v = 3.2 m/s
(a) larger than that in the previous problem.
(b) equal to that in the previous problem.
(c) smaller than that in the previous problem.
A bullet with an initial velocity of 280 m/s in the +x-direction
penetrates an initially stationary block of mass 11 kg and emerges on
the other side with a final velocity of 70 m/s in the +x-direction. The
velocity of the block after the collision is 0.2 m/s, also in the
+x-direction. Assume the block slides on a horizontal frictionless
What is the mass of the bullet?
(a) 0.01 kg
(b) 0.02 kg
(c) 0.03 kg
(d) 0.04 kg
(e) 0.05 kg
(a) smaller than 0.2 m/s.
(b) equal to 0.2 m/s.
(c) larger than 0.2 m/s.