A mass vibrates back and forth from the free end of an ideal spring (k = 20. N/m) with an amplitude of 0.30m. What is the kinetic energy of this vibrating mass when it is 0.30 m from its equilibrium position?
A) 0.45 J
B) 1.4 J
C) 0.90 J
D) zero
E) It is impossible to give an answer without knowing the object's mass.

Question

Quizplus · Accepted Answer

At the amplitude (0.30 m from equilibrium), the mass is momentarily at rest, so its kinetic energy is zero.

A Mass Vibrates Back and Forth from the Free End