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 112. The exam period was 90 minute; the mean score was 97.6; the median score was 103. Click here to see the formula sheet that came with the exam.

Unless otherwise stated, ignore air resistance and assume the acceleration of gravity is g = 9.81 m/s^{2} vertically downward.

Two stones are released from rest at a height of 600 m, one 3 s after the other, and fall vertically downward.

During the time interval that both stones are in flight, the difference in their speeds will

(a) increase. (b) decrease. (c) stay the same.

(a) Δt < 3.0 s (b) Δt = 3.0 s (c) Δt > 3.0 s

(a) 18.7 m (b) 31.4 m (c) 53.8 m (d) 103 m (e) 165 m

A block of mass M = 7.3 kg is supported on a frictionless ramp by a spring having a constant k = 106 N/m. When the ramp is horizontal, as in view a) below, the equilibrium position of the mass is at x = 0. The angle of the ramp is then changed to 20°, as in view b) below.

What is the new equilibrium position of the block, x_{1}?

(a) 0.11 m (b) 0.13 m (c) 0.20 m (d) 0.23 m (e) 0.28 m

(a) 17.6 N (b) 25.4 N (c) 33.7 N (d) 39.1 N (e) 47.6 N

A space telescope of mass m_{t} = 30,000 kg is in a stable orbit above the Earth at an altitude h = 2320 km. The radius and mass of the Earth are R_{E} = 6370 km and M_{E} = 6 × 10^{24} kg, respectively. Newton's gravitational constant is G_{N} = 6.672 × 10^{-11} N m^{2}/kg^{2}.

Once in orbit, what is the force of gravitational attraction on the space telescope due to the Earth?

(a) 103,000 N (b) 127,000 N (c) 159,000 N (d) 177,000 N (e) 196,000 N

(a) (b) (c)

(a) shorter. (b) longer. (c) the same.

(a) θ = 17.6° (b) θ = 21.3° (c) θ = 27.8° (d) θ = 31.2° (e) θ = 34.5°

A physics 211 student is trying to pull a box of books of mass m = 80 kg across the floor as shown in the following figure. The coefficient of static friction is μ_{S}.

If the angle 0 < θ < 90°, the normal force, N is:

(a) N < mg (b) N = mg (c) N > mg

(a) T = 187 N (b) T = 212 N (c) T = 243 N (d) T = 288 N (e) T = 302 N

(a) 66 km/hr (b) 73 km/hr (c) 89 km/hr (d) 97 km/hr (e) 103 km/hr

Ms. Stick hangs a picture of her family on the wall. The picture has mass m = 1.50 kg and hangs from two massless strings which are fixed to a common point on the wall. The picture hangs so that θ_{1 } = θ_{2} = 20°.

What is the tension T_{1}?

(a) 21.5 N (b) 26.4 N (c) 29.8 N (d) 32.5 N (e) 34.0 N

(a) The tension decreases. (b) The tension stays the same. (c) The tension increases.

Two boxes are pulled across a surface by a falling weight as shown below. The coefficients of static and kinetic friction between the boxes and the surface are μ_{S} and μ_{K}, respectively. Neglect the masses of the ropes and the pulley.

For the frictionless case (μ_{S} = μ_{K} = 0) what is the relationship between T_{1} and T_{2}?

(a) T_{1} > T_{2} (b) T_{1} = T_{2} (c) T_{1} < T_{2}

(a) a = g / 6 (b) a = g / 5 (c) a = g / 4 (d) a = g / 3 (e) a = g / 2

(a) a_{f} > a (b) a_{f} = a (c) a_{f} < a

(a) μ_{S} = 0.10 (b) μ_{S} = 0.20 (c) μ_{S} = 0.30 (d) μ_{S} = 0.40 (e) μ_{S} = 0.50

A tennis ball of weight W = 0.3 N is attached to a rope and swung in a vertical circle. The rope is L = 1.4 m in length. When the ball is at its highest point, the tension in the rope is measured to be zero.

What is the tangential velocity of the ball at its highest point?

(a) 1.9 m/s (b) 2.3 m/s (c) 3.7 m/s (d) 4.6 m/s (e) 5.8 m/s

(a) W (b) W (1+v^{2}/gL) (c) W (1-v^{2}/gL)

(T) True (F) False

Tiger Woods hit a "hole-in-one" on the first hole of the PGA Open golf tournament (held in Flatlands, Illinois). This golf course is perfectly flat. Tiger hit the golf ball such that it initially made a 45° angle with respect to the horizontal. There was no wind during the shot. The golf ball fell directly into the hole, a distance of 187.7 m away! In the following two questions, neglect the effect(s) of air resistance.

What was the golf ball's initial speed?

(a) 28.7 m/s (b) 36.4 m/s (c) 42.9 m/s (d) 55.3 m/s (e) 61.9 m/s

(a) 46.9 m (b) 53.9 m (c) 58.0 m (d) 63.2 m (e) 69.7 m