A rock is thrown vertically upward from the ground with an initial speed 15m/s.

A. How high does go
B. How much time is required for the rock to reach its maximum height?
C. What is the rock's height at t=2.00s?

It's all a matter of applying the various equations of motion:

A. Use
v_f ^2 - v_i^2 = 2ad


You've been given the rock's initial velocity, and you know the rock's velocity at its highest point is 0. Set a = g = -9.8m/s, and solve for d.

B. Use v_f = v_i + at and solve for t.

C. Use x = x_0 + v_i t + \frac 1 2 a t ^2 .

Post back with your answers and we'll check it for you.