A compressed spring catapult launches a 0.50kg ball vertically upward. The ball rises to a maximum height of 8.0m above the launch point. Assume no energy losses and take g=9.8m/s2.
a. (i) Calculate the gravitational potential energy gained by the ball at its highest point.
b. (ii) If the spring was compressed by 0.15m before release, determine the spring constant of the spring.