A 0.26 kg rock is thrown vertically upward from the top of a cliff that is 30 m high. When it hits the ground at the base of the cliff the rock has a speed of 25 m/s. (a) Assuming that air resistance can be ignored, find the initial speed of the rock. (b) Find the greatest height of the rock as measured from the base of the cliff. I got part (a) to be 6.0 m/s, but do not know how to get part (b). If I know both velocities, what equation should I use to find max height? Thank you!