A ball is thrown into the air by a baby alien on a planet in the system of Alpha Centauri with a velocity of 21ft/s. Its height in feet after t seconds is given by y=21t−25t 2
. Find the average velocity for the time period beginning when t=1 and lasting .01 s : .005 s : .002 s : .001 s : NOTE: For the above answers, you may have to enter 6 or 7 significant digits if you are using a calculator. Estimate the instanteneous velocity when t=1.