Physics kinetics circular motion

Question

The spring has a constant of 150Nm. If a block of mass 2kg is placed on the spring and the spring is compressed by .45m, how much elastic potential energy does the spring hold? And how fast will the block be traveling when it is released.

Answer 1

This is not a problem in circular motion.

Potential energy:

U = kx²/2

You know k and x. Plug in the numbers and get U in joules. To get the speed upon release, set U equal to kinetic energy mv²/2 and solve for v.

U = mv²/2 ⇒

v = √(2U/m)

You found U in the first part of the problem, and you know m. Plug in the numbers and get v in m/s.