differential equation A mass that weighs 32 lb. is attached to the free end of an undamped spring that is stretched 1 ft. by a force of 4 lb. Beginning at time t = 0 (seconds), an external force F(t)...

differential equation

A mass that weighs 32 lb. is attached to the free end of an undamped spring that is stretched 1 ft.
by a force of 4 lb. Beginning at time t = 0 (seconds), an external force F(t) = cos(2t) is applied
to the mass, but at time t = 2π, this force is turned off (abruptly discontinued) and the mass is
allowed to continue it motion unimpeded.
(a) Write the differential equation that models the motion of this spring-mass system.