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 78.6; the median was 81. Click here to see page1 page2 page3 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/s^{2} downward and ignore any effects due to air resistance.

A small block of mass 0.2 kg starts from rest at position O on the frictionless slide shown in the figure. When the block passes the point A, its speed is 1.3 m/s.

What is the difference in height, h, of point O and point A?

(a) 0.086 m (b) 0.097 m (c) 0.11 m (d) 0.12 m (e) 0.13 m

(a) 0.08 J (b) 0.11 J (c) 0.14 J (d) 0.17 J (e) 0.20 J

(a) 8.8 m/s^{2} (b) 9.8 m/s^{2} (c) 11.8 m/s^{2} (d) 13.9 m/s^{2} (e) 16.9 m/s^{2}

(a) upward (b) horizontal (c) downward

(a) 1.5 m/s (b) 2.6 m/s (c) 3.7 m/s (d) 4.8 m/s (e) 5.9 m/s

There are two small space ships A and B of the same mass of 5000 kg. The initial velocity of each of these ships is V = 0. A space walker of total mass 120 kg jumps from space ship A to B. Her speed relative to space ship B is 5 m/s before landing on B.

What is the magnitude of the impulse she imparts to spaceship A when she jumps?

(a) 200 Ns (b) 300 Ns (c) 400 Ns (d) 500 Ns (e) 600 Ns

(a) The total energy increases. (b) The total energy decreases. (c) Insufficient information is given to answer this question.

There is an incline with a 35° slope. The slope is rough. You pull a block of mass 3.0 kg upward along the slope, for a distance of 5 m, at a constant speed of 2.2 m/s. You have to exert a force of 20 N parallel to the slope, as shown in the figure.

What is the magnitude of the work done by friction on the block?

(a) 4.3 J (b) 7.3 J (c) 15.7 J (d) 20.5 J (e) 40.6 J

(a) 4.3 J (b) 7.3 J (c) 15.2 J (d) 30.5 J (e) 85.3 J

There is a merry-go-round of radius 3 m, which completes one rotation every 2.5 seconds at a constant angular velocity. You are standing on the edge of the merry-go-round.

What is your acceleration?

(a) 10.9 m/s^{2} outward (b) 10.9 m/s^{2} tangent to the edge (c) 10.9 m/s^{2} inward (d) 18.9 m/s^{2} outward (e) 18.9 m/s^{2 } inward

(a) land inside the merry-go-round. (b) land again on the edge. (c) land off the merry-go-round.

Two dry ice pucks slide on a horizontal, frictionless surface. Puck A moves at θ = 120° to Puck B, as shown in the figure. Puck B moves in the negative y direction. The pucks collide near the point marked X in the diagram. After the collision Puck A and Puck B are moving in the negative y and positive x directions, respectively. The initial speed of Puck A is 3 m/s and the initial speed of Puck B is 6 m/s. All the pucks have equal mass of 1 kg.

What is the final speed of puck B?

(a) 2.6 m/s (b) 3.9 m/s (c) 4.2 m/s (d) 5.1 m/s (e) 9.8 m/s

(a) 2.2 m/s (b) 3.9 m/s (c) 4.2 m/s (d) 4.5 m/s (e) 5.4 m/s

(a) None, energy is conserved. (b) 9.0 J (c) 19 J (d) 27 J (e) 45 J

Consider a block attached by a massless rope to a massive pulley. The block has a mass of 3 kg, and the pulley has a moment of inertia I = 0.01 kg m^{2} and radius 0.1 m. The block starts from rest. When the block has fallen 2 m the pulley is rotating at 8.0 revolutions per second.

How fast is the block falling?

(a) 1.0 m/s (b) 2.0 m/s (c) 5.0 m/s

(a) 12.6 J (b) 13.5 J (c) 19.8 J

Consider a flywheel that, starting from rest, is spun up with constant angular acceleration α = 5.0 rad/s^{2}.

How many revolutions does the flywheel go through before it reaches its final speed of 3000 revolutions per minute?

(a) 30.5 (b) 511 (c) 1571 (d) 8137 (e) 12496

(a) R / 2 (b) 2 R (c) 4 R

(a) 5.0 s (b) 63 s (c) 128 s

A block of mass 7 kg explodes into two blocks, one of mass 3 kg and the other of mass 4 kg, as shown in the Figure. Before the explosion the block has a momentum of 6 kg m/s in the +x direction.

What is the x component of the velocity of the center of mass after the explosion?

(a) 0.86 m/s (b) 3.2 m/s (c) 7.7 m/s

(a) -0.4 m/s (b) 0.0 m/s (c) +1.3 m/s

(a) 0 m (b) 3.0 m (c) 5.1 m

(a) W < 0 (b) W = 0 (c) W > 0

(a) 30° (b) 45° (c) It does the same amount of work in both cases.