The drive chain in a bicycle is applying a torque of 0.945 N m to the wheel of the bicycle. Treat the wheel as a hoop with a mass of 0.740 kg and a radius of 35.0 cm. What is the angular acceleration of the wheel?

11. The drive chain in a bicycle is applying a torque of 0.945 N m to the wheel of the bicycle. Treat the wheel as a hoop with a mass of 0.740 kg and a radius of 35.0 cm. What is the angular acceleration of the wheel?
A. 7.30 rad/s2 B. 10.4 rad/s2 C. 4.20 rad/s2 D. 3.64 rad/s2 E. 20.8 rad/s2
12. A piece of dirt (0.01 kg) is stuck in the tread of a spinning bicycle wheel. If the wheel is spinning at 60 RPM (rev/min) and the wheel has a radius of 0.35 meters, what is the magnitude of acceleration of the piece of dirt?
A. 2 m/s2 B. 5 m/s2 C. 10 m/s2 D. 18 m/s2 E. 14 m/s2
13. A metal bar has a frictionless axle going through its center of mass. You notice that the bar is not level (flat), but that it is tilted at a 30 degree angle (the right end is below the horizontal and the left end is above the horizontal) and that the bar is not rotating away from this orientation. You can say that:
A. The net force isn’t zero and the net torque is counter-clockwise on the bar. B. The net force is zero but the net torque is counter-clockwise in the bar. C. The net force is zero but the net torque is clockwise on the bar. D. The net force isn’t zero and the net torque is clockwise on the bar. E. The net force is zero and the net torque is zero on the bar.
14. Mars has about 1/10 the mass of the Earth and a radius 1/2 that of the Earth. Approximately, what is the acceleration of gravity (g) on Mars?
A. 25 m/s2 B. 10 m/s2 C. 4 m/s2 D. 2 m/s2 E. 12 m/s2
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15. Mars has a radius 3.41 x 106 m and a mass of 6.42 x 1023kg. What is the acceleration due to gravity on the surface of Mars?
A. 3.7 m/s2 B. 9.8 m/s2 C. 14.7 m/s2 D. 15.9 m/s2 E. 1.26 x 107 m/s2
16. An object of mass 7.0 kg is released from rest a certain height above the ground. Just before it strikes the ground it has a kinetic energy of 1750 J. From what height was the object dropped? Ignore air resistance and use g = 10 m/s2.
A. 0.0 m B. 30 m C. 15 m D. 10 m E. 25 m
17. Below, a set of five dumbbells are shown, where the weights have been moved around to different locations along the bar. The mass of the dumbbell in each case is the same as in all the others. Which dumbbell would require the greatest torque in order to rotate it about the axis indicated by the dashed line with a constant angular acceleration of 5 rad/s2?
A. B. C.
D. E.
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18. A firecracker, initially at rest on a level, frictionless table, explodes into three fragments. The momentum vectors of two of the fragments are shown, as viewed from above. What would the momentum vector of the third fragment have to be? Each grid unit represents one kilogram-meter- per-second (kg·m/s).
x
y 1p 
2p 
A.    3 ˆ ˆ2 kg m/s 1 kg m/sp x y    
B.    3 ˆ ˆ6 kg m/s 1 kg m/sp x y      
C.  3 ˆ7 kg m/sp x   
D.    3 ˆ ˆ2 kg m/s 5 kg m/sp x y      
E.    3 ˆ ˆ2 kg m/s 5 kg m/sp x y    
19. In a particular case, to stretch a relaxed muscle 2.6 cm requires a force of 25 N. Find the Young’s modulus for the muscle tissue, assuming it to be a uniform cylinder of length 0.24 m and cross-sectional diameter of 8.2 cm.
A. 12500 N/m2 B. 25040 N/m2 C. 53500 N/m2 D. 43700 N/m2 E. 35050 N/m2
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20. A 0.100 kg rubber ball is thrown horizontally with a speed of 10 m/s at a vertical wall. The ball rebounds with the same speed. The force of the collision on the ball is shown in the graph below.
( )t s
( )F N
maxF
0.010 s What is the value of the maximum force?
A. 2 N B. 20 N C. 2000 N D. 200 N E. Impossible to tell.