A 0.75-kg mass is attached to the lower end of a coil spring suspended from the ceiling and having a spring constant of 36 N/m. The resistance in the spring-mass system is numerically equal to the instantaneous velocity. At t= 0 the mass is set in motion from a position 0.5 m below its equilibrium position by giving it an upward velocity of 0.25 m/s. Write an initial value problem that models the given situation.

A 0.75-kg mass is attached to the lower end of a coil spring suspended from the ceiling and having a spring constant of 36 N/m. The resistance in the spring-mass system is numerically equal to the instantaneous velocity. At t= 0 the mass is set in motion from a position 0.5 m below its equilibrium position by giving it an upward velocity of 0.25 m/s. Write an initial value problem that models the given situation.