A ball with m = .5 kg is thrown from the building (40m height) withinitial velocity 15 m/s downwards, hits a spring on the ground withk=700 Nm and bounces back. Find :
a) the velocity of the ball just before it hits the spring.
b) the maximum compression of the spring
c) the maximum height that the ball will bounce up
d) time it takes to reach the maximum height.