A ball is thrown into the air by a baby alien on a planet in the system of Alpha Centauri with a velocity of 30 ft/s. Its height in feet after t seconds is given by y=30t-10t^2. a) Find the average velocity over the time interval [2,2+ h] where h is given as follows: h= 0.1 ft/s h= 0.01 ft/s h= 0.001 ft/s Estimate the instantaneous velocity when t= 2 ft/s