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 107. The exam period was 90 minutes; the mean score was 87.9; the median score was 92. 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.

Three boxes are connected by massless strings and are resting on a frictionless table. Each box has a mass of 15 kg and the tension T_{1} in the right string is accelerating the boxes to the right at a rate of 2.5 m/s^{2}.

What is the magnitude of the force T_{1}?

(a) 37.5 N (b) 75.0 N (c) 113 N (d) 157 N (e) 192 N

(a) 11.3 m (b) 18.8 m (c) 20.0 m

(a) 37.5 N (b) 75.0 N (c) 113 N

(a) 75.0 N to the left (b) 37.5 N to the left (c) 37.5 N to the right (d) 75.0 N to the right (e) 113 N to the right

A block of mass M is attached to the ceiling of an elevator by two strings.

Which one of the following equations applies to this system when the elevator is at rest?

(a) T_{1} cosθ_{1} + T_{2} cosθ_{2} = 0 (b) T_{1} sinθ_{1} - T_{2} sinθ_{2} = 0 (c) T_{1} cosθ_{1} + T_{2} cosθ_{2} = Mg (d) T_{1} sinθ_{1} + T_{2} sinθ_{2} = Mg (e) T_{1} = T_{2}

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

A 200 kg crate sits on the bed of a truck. The truck is accelerating to the right at 1.0 m/sec^{2}. The static coefficient of friction between the crate and the truck bed is μ_{s} = 0.25. The kinetic coefficient is μ_{k} = 0.15. The crate does not slide relative to the truck bed.

The direction of the friction force on the crate from the truck is

(a) to the left. (b) to the right.

(a) 490 N (b) 294 N (c) 200 N (d) 50 N (e) 30 N

(a) 8 m/sec^{2} to the right (b) 1.5 m/sec^{2} to the right (c) zero (d) 1.5 m/sec^{2} to the left (e) 8 m/sec^{2 }to the left

A Ferris wheel has a radius of 8 meters, and spins counterclockwise with a constant angular velocity ω = 0.8 radians/second. (Cart B is going up at the instant shown.)

What is the speed of the cart A at the instant shown?

(a) 0 (b) 6.4 m/s (c) 8.0 m/s

(a) -9.8 m/s^{2} (b) -5.1 m/s^{2} (c) 0 (d) 5.1 m/s^{2} (e) +9.8 m/s^{2}

(a) 380 N (b) 740 N (c) 1120 N

Scientists want to place a 2800 kg satellite in a circular orbit around Mars. They plan to have the satellite orbit at a speed of 2100 m/s.

m_{mars} = 6.5 × 10^{23} kg r_{mars} = 3.40 × 10^{6} m G = 6.67 × 10^{-11} N-m^{2}/kg^{2}

How far above the surface of mars will the satellite orbit?

(a) 3.4 × 10^{6} m (b) 5.1 × 10^{6} m (c) 6.4 × 10^{6} m (d) 7.3 × 10^{6} m (e) 8.5 × 10^{6} m

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

A box is attached to a spring with a spring constant of 350 N/m on a frictionless incline that makes an angle of 30° with respect to horizontal as shown. The box is at rest when the spring is stretched 0.15 meters from its equilibrium length.

What is the mass of the box?

(a) 5.4 kg (b) 6.2 kg (c) 10.7 kg

(a) 1.4 m/s (b) 2.0 m/s (c) 2.8 m/s

An airplane travels with a velocity of 150 m/s due east with respect to the air. The air is moving with a speed of 50 m/s with respect to the ground at an angle of 45° north of east.

What is the speed of the plane with respect to the ground?

(a) 154 m/s (b) 185 m/s (c) 188 m/s

(a) 11° north of east (b) 16° north of east (c) 19° north of east

A cannon ball is fired at a wall located 450 meters away (the diagram is not to scale). The initial horizontal component of the balls velocity is 90 m/s and its initial angle is 24°.

What is the initial speed of the ball?

(a) 75 m/s (b) 99 m/s (c) 114 m/s

(a) 5.0 s (b) 5.5 s (c) 8.2 s

(a) 82 m (b) 164 m (c) 246 m

(a) 34 m (b) 78 m (c) 128 m

The graph below shows data obtained with the Physics 211 cart, track and motion detector. The position of a cart is shown as a function of time. The time interval between measurements is 0.05 s.

Which one of the following statements about the velocity of the cart is correct?

(a) The velocity of the cart is positive from 0 s to 5 s. (b) The velocity of the cart is positive from 1 s to 4 s. (c) The velocity of the cart is positive only at 2.5 s. (d) The velocity of the cart is positive from 1 s to 2 s. (e) The velocity of the cart is positive from 3 s to 4 s.

(a) From 1 s to 4 s the acceleration of the cart goes from positive to negative. (b) From 1 s to 4 s the acceleration of the cart goes from negative to positive. (c) The acceleration of the cart does not change sign between 1 s and 4 s.

(a) 1.0 m/s (b) 0.8 m/s (c) -0.2 m/s (d) -0.6 m/s (e) -0.8 m/s