Potential Energy (Gravitational and Spring) Practice Test

A spring in a pinball machine is compressed from its equilibrium position. It is released and it fires the pinball at a velocity of into play. No energy is lost to friction and all of the energy in the spring is transferred to the pinball. What is the spring constant in the spring?

A massless spring rests horizontally on a table, with its right end attached to a block and with its left end attached to a wall. The block is then pushed against the spring, compressing it from its equilibrium position. After being released, the block's velocity as it moves back through the equilibrium point is . What is the spring constant of this spring?