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 110.
The exam period was 90 minutes; the average score was 88.5; the median
score was 92. Click here to see page1
page2 of the formula sheet that came
with the exam.
Unless told otherwise, you should assume that the
acceleration of gravity near the surface of the earth is 9.8
m/s2 downward and ignore any effects due to air
A hydraulic lift with a rectangular platform of area A = 9
m2 is used to raise cars above the ground. The
cross-sectional area of the narrow, fluid-filled tube connected to the
lift-platform is 0.05 m2 (as shown in the figure).
If a 720-kg car is placed on the lift-platform what force F
must be applied to the small piston to balance the weight of the
(a) 9.8 N
(b) 14.3 N
(c) 28.4 N
(d) 39.2 N
(e) 46.5 N
(a) d = 23 cm
(b) d = 147 cm
(c) d = 396 cm
Water (ρw = 1000 kg/m3) flows though a
cylindrical pipe of radius R1 = 8 cm with an unknown speed of
v1. The pipe then narrows to a radius R2 = 3.2 cm
where the water has a speed of v2 = 8.13 m/s.
What is the speed of the water in the wide region of the pipe?
(a) v1 = 1.3 m/s
(b) v1 = 3.3 m/s
(c) v1 = 8.1 m/s
(d) v1 = 20 m/s
(e) v1 = 51 m/s
(a) 1.9 × 103 s
(b) 3.9 × 103 s
(c) 4.3 × 103 s
(d) 5.1 × 103 s
(e) 6.8 × 103 s
(a) 4 kPa
(b) 18 kPa
(c) 32 kPa
(d) 41 kPa
(e) 55 kPa
A string is attached to a cube of wood of volume V = 0.3
m3 that is placed in fresh water with density 1000
kg/m3, as shown in the figure below. The tension in the
string, T, is 520 N.
What is the density of the wood?
(a) 212 kg/m3
(b) 496 kg/m3
(c) 614 kg/m3
(d) 823 kg/m3
(e) 1043 kg/m3
(a) smaller than 520 N
(b) equal to 520 N
(c) larger than 520 N
An open U shaped tube is initially partially filled with water
(ρw = 1000 kg/m3). An 10 cm high column of
oil (ρoil = 800 kg/m3) is carefully poured
into the right side of the tube (see picture). What is the height H of
the oil above the water?
(a) H = 1 cm
(b) H = 2 cm
(c) H = 3 cm
(d) H = 4 cm
(e) H = 5 cm
A block suspended from a scale has a weight of 3 N. The block is then
lowered into a glass of water so that it is completely submerged and the
reading on the scale is 2.4 Newtons. (The density of water is
What is the volume of the block?
(a) 8.94 × 10-6 m3
(b) 3.01 × 10-5m3
(c) 6.12 × 10-5 m3
(d) 1.04 × 10-5 m3
(e) 4.06 × 10-4 m3
(a) remain at 2.4 N.
(a) 100 m
(b) 200 m
(c) 300 m
(d) 400 m
(e) 500 m
(a) 128 kg
(b) 332 kg
(c) 480 kg
(d) 594 kg
(e) 932 kg
A 7.0 kg block is resting on a horizontal frictionless surface. A
force F pushes the block to the right and a spring with spring
constant 150 N/m pushes the block to the left, such that the block is in
equilibrium. At time t = 0 the force F is removed and the mass
oscillates back and forth with a maximum speed v = 2.1 m/s.
How long does it take the block to complete one oscillation?
(a) 0.43 s
(b) 1.2 s
(c) 1.4 s
(a) F = 68 N
(b) F = 73 N
(c) F = 91 N
(d) F = 120 N
(e) F = 150 N
(a) 1.21 m/s
(b) 1.69 m/s
(c) 1.79 m/s
(d) 2.05 m/s
(e) 2.41 m/s
(a) v(t) = Vmax cos(ωt)
(b) v(t) = -Vmax cos(ωt)
(c) v(t) = -Vmax sin(ωt)
A simple 3 kg pendulum is suspended from the ceiling of an elevator.
When the elevator is at rest, the period of the pendulum is 0.75
What is the length of the pendulum string?
(a) 0.14 m
(b) 0.24 m
(c) 0.34 m
(a) moving up with a constant speed.
(b) moving down with a constant speed.
(c) accelerating up.
(d) accelerating down.
(e) at rest and it is not accelerating.
Standing 10 meters from a stopped ambulance, you notice the siren is
120 dB and the pitch is 500 Hz. Another day, while standing by the side
of a road, you see the same ambulence driving and hear the siren but it
is only 80 dB and the pitch is 540 Hz. (The speed of sound in air is 340
What is the speed of the ambulance?
(a) 27 m/s
(b) 25 m/s
(c) 23 m/s
(a) toward you
(b) away from you.
(a) 100 m
(b) 1000 m
(c) 10000 m
A harpsichord string (fixed at both ends) is 0.8 meters long. The
fundamental frequency is 500 Hz and the tension in the string is 158
newtons. (The speed of sound in air is 340 m/s.)
What is the speed of the transverse wave in the string?
(a) 600 m/s
(b) 700 m/s
(c) 800 m/s
(a) 2.5 × 10-4 kg/m
(b) 3.5 × 10-4 kg/m
(c) 4.5 × 10-4 kg/m
(a) 0.68 m
(b) 0.80 m
(c) 1.5 m
(a) 0.53 m
(b) 0.78 m
(c) 0.91 m