If a ball is thrown into the air with a velocity of 40 ft/s, its height in feet after t seconds is given by y=40t−16t2.
a. Find the average velocity for the time period beginning when t=2 and lasting
(i) 0.5 second,
(ii) 0.1 second,
(iii) 0.05 second,
(iv) 0.01 second.
b. Find the instantaneous velocity when t=2.