1. A 10-Ib weight is suspended by a spring that is stretched 2 inches by the weight. Assume a resistance whose magnitude is 20/sqrt g times the instantaneous velocity in feet per second. If the weight is pulled down 3 inches below its equilibrium position and released, find the time required to reach the equilibrium position for the first time

A weight of 80 lb stretches a spring 8 ft. The weight is pulled down 3 it below the equilibrium position and then released. What initial velocity vo given to the weight would have the effect of doubling the amplitude of the vibration? Use g = 32 ft/sec" VO fu/sec (Type an exact answer, using radicals as needed