(1 pt) this problem is an example of critically damped harmonic motion. a hollow steel ball weighing 4 pounds is suspended from a spring. this stretches the spring 18 feet. the ball is started in motion from the equilibrium position with a downward velocity of 4 feet per second. the air resistance (in pounds) of the moving ball numerically equals 4 times its velocity (in feet per second) . suppose that after t seconds the ball is y feet below its rest position. find y in terms of t. take as the gravitational acceleration 32 feet per second per second. (note that the positive y direction is down in this problem.) y=