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 108.
The exam period was 90 minutes. The mean score was 78.1; the median was
79. Click here to see the formula sheet
that came with the exam.
(a) (Vx, Vy) = (6.3 m/s, 1.6 m/s)
(b) (Vx, Vy) = (2.8 m/s, 4.9 m/s)
(c) (Vx, Vy) = (8.6 m/s, 2.6 m/s)
(d) (Vx, Vy) = (9.3 m/s, 5.3 m/s)
(e) (Vx, Vy) = (4.6 m/s, 1.4 m/s)
(a) |scm| < 75 mph
(b) |scm| = 75 mph
(c) |scm| > 75 mph
A 4.0 kg circular disk slides in the x-direction on a
frictionless horizontal surface with a speed of 5.0 m/s. It collides
with an identical disk that is at rest before the collision. The
collision is elastic. Disk 1 goes off at an angle of 60° with
respect to the x-direction. Disk 2 goes off at an angle of
30° with respect to the x-direction. Treat the disks as
point objects and ignore the possible rotations of the disks.
Which one of the following statements is correct?
(a) Disk 1 has the greater kinetic energy after the collision.
(b) Disk 2 has the greater kinetic energy after the collision.
(c) The kinetic energies of the two disks are equal after the collision.
(a) 2.5 m/s
(b) 2.8 m/s
(c) 3.3 m/s
(d) 3.9 m/s
(e) 4.3 m/s
(a) 0 J
(b) 25 J
(c) 50 J
(d) 75 J
(e) 100 J
In a Physics 211 laboratory experiment one end of a string is tied to
a cart. The other end of the string is tied to a force probe that is
fixed to the track. The cart is free to move on the track. Initially
the string is slack. The cart is given a velocity
vo and the magnitude of the momentum of the
cart is 0.42 kg m/s. The experimental setup is shown below.
The string becomes taut, and a force is exerted on the cart by the
string. The string then becomes slack again. The force on the cart is
measured as a function of time by the force probe. The data from the
force probe are shown below. The integral of force on the cart with
respect to time is 0.66 kg m/s.
Find how long the string exerted a force on the cart.
(a) 0.2 s
(b) 1.1 s
(c) 2.4 s
(a) 0.24 kg m/s
(b) 0.42 kg m/s
(c) 0.66 kg m/s
(d) 0.90 kg m/s
(e) 1.24 kg m/s
Ricardo (R) and Maria (M) are in a canoe that is stationary and
floating on a calm lake. They are 4.0 m apart, symmetrically located
about the center of the canoe as shown in the figure on the left.
Ricardo has mass 80 kg Maria has a mass of 62 kg. The canoe is massless
and is free to move in the water without friction.
If Ricardo and Maria both move to the center of the canoe what
distance d will the canoe move relative to a rock that is
stationary in the water?
(a) d = 0 (The canoe will not move.)
(b) d = 0.15 m
(c) d = 0.25 m
(d) d = 0.35 m
(e) d = 0.55 m
(a) is to the right.
(b) is to the left.
(c) is zero.
A ballistic pendulum like the one demonstrated in lecture has mass
M = 2 kg. The ballistic pendulum begins at rest and is struck by
a ball of mass m = 0.25 kg, which sticks to the pendulum. The
pendulum is observed to rise a maximum height h above its
During which of the following intervals is the total horizontal
momentum of the ball plus pendulum system conserved?
(a) while the ball is travelling through the air (before the collision)
(b) while the ball is hitting the pendulum (during the collision)
(c) while the pendulum is swinging up to its maximum height (after the collision)
(d) both a. and b.
(e) both b. and c.
(a) 9 m/s
(b) 24 m/s
(c) 27 m/s
How do the accelerations A1 and
(a) A1 > A2
(b) A1 = A2
(c) A1 < A2
A young boy of mass m = 25 kg sits on a coiled spring that has
been compressed to a length 0.4 m shorter than its uncompressed length
and then held at this length. Suddenly the spring is released, and the
boy flies vertically into the air. He reaches a maximum distance 0.5 m
above his initial position. The spring is ideal and massless and we
ignore the air friction.
What is the spring constant k of the spring?
(a) 766.4 N/m
(b) 1532.8 N/m
(c) 613.1 N/m
(a) 1.1 m/s
(b) 1.4 m/s
(c) 1.7 m/s
(d) 1.9 m/s
(e) 2.1 m/s
(The mass and radius of the earth are ME = 5.98
× 1024 kg and RE = 6,380 km
respectively, and Newton's gravitational constant is G = 6.67300
× 10-11 m3 kg-1 s-2.
You should ignore any effects due to air resistance and the rotation of
(a) 6 km/s
(b) 11 km/s
(c) 14 km/s
(d) 21 km/s
(e) 25 km/s
Here is a graph from Physics 211 Lab 4. The basketball of mass
m = 0.62 kg was released from the height h and it started
bouncing. The numbers on the graph correspond to the maxima of its
From what height h was the ball released? Ignore air
(a) 1.01 m
(b) 1.82 m
(c) 2.23 m
(a) The step-like dependence of the "Total" energy on time
demonstrates the violation of the energy conservation law.
(b) The graph demonstrates that the "Total" energy is conserved throughout
the entire four-second interval.
(c) The step-like dependence of the "Total" energy on time corresponds to
the mechanical energy dissipation via its transformation into other
What is the speed V2 of the ball when it reaches a
point in its swing which is level with O2?
(a) 2.21 m/s
(b) 3.96 m/s
(c) 4.29 m/s
(d) 4.83 m/s
(e) 5.11 m/s
How much work W is done on this spring when it is stretched by
an amount x from its relaxed position?
(a) W = (1/2)Kx2
(b) W = (1/3)Kx3
(c) W = (1/4)Kx4
During a time interval Δt the magnitude of the work
W done by the frictional force is
(a) |W| = Mg tanθ (VΔt)
(b) |W| = Mg sinθ (VΔt)
(c) unknown, since the coefficient of kinetic friction is not given.
A box of mass M slides on a horizontal floor with initial
speed V0. The kinetic coefficient of friction between
the box and the floor is μk.
After sliding a distance D the speed of the box is
¾V0. What is the magnitude of the macroscopic
work W done by the frictional force on the box during this
(a) |W| = (1/4) MV02
(b) |W| = (7/32) MV02
(c) |W| = (3/4) MV02
(d) |W| = (3/4) MgμkD
(e) |W| = Mgμk / D
(a) V1 < ¾ V0
(b) V1 = ¾ V0
(c) V1 > ¾ V0
Identical constant forces push two blocks A and B over identical
horizontal surfaces for identical periods of time. The masses are
initially at rest. The mass of A is twice the mass of B.
Which block ends up with the biggest momentum?
(a) block A
(b) block B
(c) Both blocks end up with the same momentum.
(a) block A
(b) block B
(c) Both blocks end up with the same kinetic energy.
(a) 0.6 kg
(b) 0.8 kg
(c) 1.2 kg
(d) 1.8 kg
(e) 2.4 kg