) The acceleration of a free-falling object on the moon is given by the formula . If a rock is dropped from a height of 20 m on the moon: a) find a formula for the velocity of the rock, v(t), at time t. Note: You can think of this as an initial value problem to solve because acceleration is the derivative of the velocity, and you are given information about the initial velocity. b) find a formula for the height of the rock, s(t), at time t. Note: Again, you can think of this as an initial value problem because velocity is the derivative of height, and you know the initial height.