At the top of a 30m hill is a 5kg mass. It is loaded into a spring cannon. The cannon's spring has a constant k= 400 N/m and the spring is compressed 40 cm. The mass is initially at rest. There is no friction.
a) what was the stored energy in the spring before it was released?
b) what was the gravitational potential energy of the mass with respect to the bottom of the hill?
c) what is the kinetic energy of the mass when it is at the bottom of the hill?
d) what is the velocity of the mass when it is at the bottom of the hill?
e) what is the ratio of energy y before to energy y after?