A 32.00-lb weight stretches a certain spring 6.40 ft when the weight and spring are placed in a fluid that resists the motion with a force equal to four times the velocity. If the weight is brought to rest and then given a velocity of 16 ft/s, find the equation of motion
A) x = 16 e^ -2x cos x
B) x = 16 e^ -2x sin x
C) x = 16 e^ -x sin 2x
D) x = 16 e^ -2x sin x +15 e^ -2x cos x