A ball with a mass of #640 g# is projected vertically by a spring loaded contraption. The spring in the contraption has a spring constant of #32 (kg)/s^2# and was compressed by #7/8 m# when the ball was released. How high will the ball go?
Begin by converting the mass of the ball to kilograms:
The reference, potential energy of the spring , gives us the equation:
we are given:
Assuming that all of the potential energy in the spring is transferred to the ball, the maximum height can be computed, using the equation for potential energy due to height:
Set the right side of equation  equal to the right side of equation :