A hot-air balloon is rising vertically with a constant speed of 2m/s. When the balloon is 60m above the ground, a passenger releases a ball. Ignore air resistance and take the upward direction as positive with g=9.8m/s2 downward.
(a) Write the initial velocity and the initial displacement of the ball at the moment of release, using the ground as the origin.
(b) Calculate the maximum height reached by the ball above the ground.
(c) Determine the time taken by the ball to reach the ground after being released.
(d) Find the velocity of the ball just before it strikes the ground.