A 2.5 kg mass is attached to a spring and oscillates with a rotational equivalent of 12 rad/s. What is the force constant of the spring? A mass M on a spring with force constant k has a rotational equivalent to. The same mass on a spring with force constant 4k will have a rotational equivalent The head of a drum vibrates in simple harmonic motion with a period of 0.13 seconds and a maximum acceleration of 305 mm/sz. What is the amplitude of the drum head