A stone is thrown vertically upward from outside a window, with an initial velocity of 24.0 m/s. It moves up, and then down to the ground 420 m below the point where it started. Let `up' be positive.
(a) What is the maximum height above the window to which the stone rises?
________m.
(b) How long is the rock in the air before it reaches the ground?
________ s.
(c) What is its velocity just before it hits the ground?
_______ m/s.