Ahollow steel ball weighing 4 pounds is suspended from a spring. this stretches the spring 12 feet. the ball is started in motion from the equilibrium position with a downward velocity of 5 feet per second. the air resistance (in pounds) of the moving ball numerically = 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. (note that the positive direction is down.) take as the gravitational acceleration 32 feet per second per second.

During the experiment if you could triple the breakaway magnetic force with all other quantities left unchanged, what is the new value for the critical velocity if it was v0 (initial velocity), initially? (b) now if you halved the radius with all other quantities left unchanged, what is the new critical velocity if it was v0 (initial velocity), initially? (c) if during the experiment, critical velocity quadrupled with all other quantities left unchanged, what is the new breakaway force if its magnitude was initially f0,?