A coin is dropped from a height of 750 feet.The height, s, (measured in feet), at time, t (measured in seconds), is given by $\displaystyle s = - 16t^2 +750$

- Find the average velocity on the interval [1,3]
- Find the instantaneous velocity when t = 3
- How long does it take for the coin to hit the ground?
- Find the velocity of the coin when it hits the ground.