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 88.9; the median was 93. Click here to see page1 page2 of the formula sheet that came with the exam.

A rope is attached to a block and a force T = 46 N is applied to pull the block up a rough incline at constant speed. The incline makes an angle of 30° with the horizontal. The mass of the block is M = 5 kg, and the block is pulled a distance D = 8 m up the incline.

What is the work done by gravity?

(a) -196 J (b) -100 J (c) 0 J (d) 100 J (e) 196 J

(a) 368 J (b) 221 J (c) 0 J

(a) -196 J (b) -100 J (c) 0 J

(a) 0 J (b) -172 J (c) -196 J

Two boxes are connected by an ideal string on a frictionless surface as shown below. The pulley is a uniform solid cylinder with radius 0.5 meters and moment of inertia I = 1.5 kg-m^{2}. The boxes are released from rest, and after the top block (M_{1}) has moved 3 meters to the right, it is observed to be traveling with a speed 4 m/s.

What is the mass of the pulley?

(a) M = 1.5 kg (b) M = 8 kg (c) M = 12 kg

(a) h = 0.5 m (b) h = 0.8 m (c) h = 1.3 m (d) h = 1.5 m (e) h = 2.8 m

(a) less than 4 m/s (b) equal 4 m/s (c) greater than 4 m/s

A 2-meter-long uniform plank has mass 15 kg. It is supported by a fulcrum 0.5 meters from the right end, and by a string attached to the ceiling at the left end as shown in the figure below.

What is the tension T_{c} in the string attached to the ceiling?

(a) T_{c} = 36 N (b) T_{c} = 49 N (c) T_{c} = 110 N

(a) F = 52 N (b) F = 98 N (c) F = 135 N

(a) 20 kg (b) 30 kg (c) 60 kg

Three point masses are attached to a rigid mass-less rod as shown below. The left mass is unknown, the middle mass is 5 kg, and the right mass is 3 kg. The center of mass for this system is 0.55 m to the right of the unknown mass.

Calculate the left-most mass M.

(a) 1 kg (b) 2 kg (c) 3 kg

(a) 4.25 kg m^{2} (b) 6.13 kg m^{2} (c) 7.75 kg m^{2}

A 0.4-meter-long (massless) wrench is being used to tighten a nut as shown in the figure. A torque is being applied by attaching a mass M to a string tied to the end of the wrench. The string is 0.3 meters long and makes an angle of 30° with the wrench.

Calculate the torque exerted on the nut by this configuration.

(a) 0.3 Mg (b) 0.3 Mg sin(30°) (c) 0.4 Mg sin(30°) (d) 0.3 Mg cos(30°) (e) 0.4 Mg cos(30°)

(a) increases. (b) remains the same. (c) decreases.

(a) block A (b) block B (c) Both blocks end up with the same kinetic energy.

(a) 1100 kg-m/s (b) 1200 kg-m/s (c) 1600 kg-m/s (d) 1800 kg-m/s (e) 2400 kg-m/s

An object of mass M = 5 kg is moving horizontally in a straight line at a speed of 6 m/s. A force of 100 N is applied over a short period of time such that the speed of the object increases to 10 m/s.

The work done by the force is

(a) 5 J (b) 15 J (c) 100 J (d) 120 J (e) 160 J

(a) 0.15 s (b) 0.20 s (c) 0.35 s

A block sits at rest on a horizontal surface. It suddenly explodes into two pieces. A piece of mass 4 kg goes to the left and a piece of mass 8 kg goes to the right. Each block slides along the frictionless surface, then up a frictionless ramp. The speed of the 4 kg block is 10 m/s immediately after the explosion.

What is the speed of the 8 kg block immediately after the explosion?

(a) 0 m/s (b) 2 m/s (c) 5 m/s (d) 6 m/s (e) 8 m/s

(a) 0.9 m (b) 3.4 m (c) 4.5 m (d) 5.1 m (e) 7.3 m

(a) They move to the left. (b) They move to the right. (c) They do not move.

Two hockey players are gliding across the ice towards the pack. Player A with mass 75 kg is moving at 3 m/s in the +x direction. Player B with mass 50kg is moving at 4 m/s in the +y direction.

What is the magnitude of their total momentum?

(a) 115 kg m/s (b) 200 kg m/s (c) 300 kg m/s (d) 400 kg m/s (e) 460 kg m/s

(a) 27° (b) 42° (c) 62°

Player A and Player B are not looking where they are going, and they both collide with Player C, also known as “Tony Zamboni”, at the same instant. Tony is not moving before the collision and has a mass of 100 kg. They all collapse together in a heap and drift across the perfectly smooth and frictionless ice.

At what speed are they moving?

(a) 0.85 m/s (b) 1.33 m/s (c) 1.65 m/s (d) 2.00 m/s (e) 2.45 m/s

A ship of mass 1.5 × 10^{5} kg and speed 8 m/s strikes a stationary iceberg of mass 1.5 × 10^{6} kg. Assume that the forces exerted by the water on the ship and on the iceberg are negligible.

What is the resulting speed of the iceberg if the ship and the iceberg are stuck together after the collision?

(a) 0.24 m/s (b) 0.31 m/s (c) 0.56 m/s (d) 0.73 m/s (e) 0.89 m/s

(a) larger than V (b) equal to V (c) smaller than V