Assignment 36. The hammer of a pile driver strikes to top of a pipe with a velocity of 7 m/s. From what height did the hammer fall? 37. A box falls from an elevator this is ascending with a velocity of 2 m/s. It strikes the bottom of the elevator shaft in 3 s. (a) How long will it take the box to reach its maximum height? (b) How far from the bottom of the shaft was the box when it fell off the elevator? 38. An aircraft shell is fired vertically upward with an initial velocity of 500 m/s. (a) Compute the maximum height of the shell. (b) How long does it take to reach this height? (c) When will the height be 1000 m?