Assignment:
Question 1. Someone shoots a gun while holding their arm stiffly outstretched in front of them and with the back of their shoulder braced against a wall. The bullet leaving the gun has a mass of 2.5 g and is traveling at 380 m/s (.22 caliber). It reaches this velocity (from rest) in 0.0001 s. Assuming that all of the recoil force is directed along the axis of the bones of the forearm, what is the stress in the arm bone? This of the arm as being one long bone, and the cross-sectional area of this bone is 3 cm2.
a. 6.8x109 dyn/cm2
b. 4.0x109 dyn/cm2
c. 9.4x108 dyn/cm2
d. 3.2x109 dyn/cm2
e. 7.2x108 dyn/cm2
Question 2. Treat this problem with the simple pendulum in mind. A person pulls a bowling ball 0.5 m behind them and lets gravity cause it to swing forward. Just as the ball reaches the highest point in front of them, they let go. What does the ball's path look like after being released?