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 123. The exam period was 90 minutes; the mean score was 84.0; the median score was 87. Click here to see page1 page2 of the formula sheet that came with the exam.

From the top of a tower it takes 3.5 seconds for a ball to fall freely to the ground (see the figure).

From the top of the tower, you throw the ball vertically downward to the ground. The ball reaches the ground 2.5 seconds later. What is the initial speed of the ball?

(a) 7.4 m/s (b) 9.6 m/s (c) 10.7 m/s (d) 11.8 m/s (e) 12.9 m/s

(a) 2.5 s (b) 2.7 s (c) 3.2 s (d) 3.4 s (e) 3.6 s

(a) θ is positive (upward). (b) θ is negative (downward). (c) not enough information

A person with body mass 55 kg is standing on the scale on an elevator.

The elevator starts to go up. What is the reading of the scale at this moment?

(a) The reading of the scale is larger than 55 kg. (b) The reading of the scale is smaller than 55 kg. (c) The reading is 55 kg.

(a) The elevator is going up. (b) The elevator is going down. (c) There is not enough information.

(a) 0.23 m/s^{2} (b) 0.45 m/s^{2} (c) 0.89 m/s^{2} (d) 0.98 m/s^{2} (e) 1.21 m/s^{2}

There is a ramp that makes an angle of 35° with the horizontal ground. The top of the ramp is 3 m from the ground. There is a moat of width 26 m beyond the ramp as illustrated in the figure.

The speed of the ball reaching the top of the ramp is 5.0 m/s. What is the height of the highest point of the trajectory of the ball from the ground?

(a) 3.2 m (b) 3.4 m (c) 3.6 m (d) 3.8 m (e) 4.0 m

(a) 5.0 m/s (b) 6.1 m/s (c) 7.3 m/s (d) 8.1 m/s (e) 9.2 m/s

(a) 11.2 m/s (b) 12.5 m/s (c) 13.3 m/s (d) 14.9 m/s (e) 15.3 m/s

The speed of your boat is 15 km/h relative to water. How long will it take for you to reach the boy?

(a) 2.2 min (b) 3.3 min (c) 4.4 min (d) 5.5 min (e) 6.6 min

(a) 10^{-11} N (b) 10^{-9} N (c) 10^{-7} N (d) 10^{-5} N (e) 10^{-3} N

Consider a one-dimensional motion of a 1.3 kg mass along the x-coordinate. The velocity v as a function of time t is graphed in the following figure.

There are moments when there is no total force acting on the mass. How many such moments are there before t = 7 sec?

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

(a) 6.5 N (b) 8.5 N (c) 13 N (d) 21 N (e) 26 N

(a) The mass does not return to the starting point. (b) The mass returns to the starting point once. (c) The mass returns to the starting point twice.

There is a vertical hoop of radius 1.2 m fixed on the ground. A small block of mass 0.7 kg is sliding along the frictionless inside surface of the hoop. Its speed is not sufficiently large, so the mass cannot run along the hoop to the highest point as illustrate blow.

Since the block falls off before reaching the top, its speed when it falls off the hoop cannot be larger than a certain value. Choose the correct answer from the following.

(a) The speed cannot exceed 1.2 m/s. (b) The speed can be larger than 1.2 m/s but cannot exceed 2.5 m/s. (c) The speed can be larger than 2.5 m/s but cannot exceed 3.2 m/s. (d) The speed can be larger than 3.2 m/s but cannot exceed 3.5 m/s. (e) The speed can be larger than 3.5 m/s.

(a) The block still falls off the hoop. (b) The block can complete the rotation along the hoop. (c) Insufficient information is supplied to answer this question.

A block A of mass M_{A} = 3 kg rests on a table and is attached by a string that runs over a frictionless, massless pulley, to a second block B of mass M_{B} = 0.75 kg (see figure). The blocks are at rest. The coefficient of static friction between block A and the table is μ_{s} = 0.3 and the coefficient of kinetic friction is μ_{k} = 0.2 .

What is the tension T in the string?

(a) 0.75 N (b) 2.5 N (c) 3 N (d) 5.75 N (e) 7.35 N

(a) μ_{s} M_{A} g (b) μ_{k} M_{A} g (c) M_{B} g

(a) a_{y} = 1.44 m/s^{2} (b) a_{y} = 0.24 m/s^{2} (c) a_{y} = -0.17 m/s^{2} (d) a_{y} = -2.0 m/s^{2} (e) a_{y} = -9.8 m/s^{2}

(a) F_{start}(Moon) = F_{start}(Earth) and F_{stop}(Moon) = F_{stop}(Earth) (b) F_{start}(Moon) = F_{start}(Earth) and F_{stop}(Moon) < F_{stop}(Earth) (c) F_{start}(Moon) < F_{start}(Earth) and F_{stop}(Moon) = F_{stop}(Earth) (d) F_{start}(Moon) < F_{start}(Earth) and F_{stop}(Moon) < F_{stop}(Earth) (e) F_{start}(Moon) > F_{start}(Earth) and F_{stop}(Moon) < F_{stop}(Earth)

Your solar powered car can manage a constant acceleration of 1 m/s^{2}. How long will it take you to cross a two-lane road (width 10 m), starting from rest (treat the car like a point, not an extended object)?

(a) 10 s (b) 7 s (c) 5 s (d) 4.5 s (e) 3.1 s

(a) T (b) 2 T (c) 4 T

(a) 9.8 m/s (b) 5 m/s (c) 4.7 m/s (d) 4.5 m/s (e) 3.1 m/s

A man pulls a group of three, rigidly connected, identical carts forward in a straight line using a rope attached to the last car (A) in the group:

Using a tension T_{A} in the rope produces an acceleration a of the carts. If he instead attached the rope to cart C and produced the same acceleration a, then the tension in the rope T_{C} obeys:

(a) T_{A} < T_{C} (b) T_{A} = T_{C} (c) T_{A} > T_{C}

(a) T_{A} (b) normal force of A on B (c) normal force of B on A (d) normal force of B on C (e) normal force of C on B