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 with t=2 and (1) lasting 0.5 seconds: -32 equation editorequation editor ft/s (2) lasting 0.1 seconds: -25.6 equation editorequation editor ft/s (3) lasting 0.05 seconds: -24.8 equation editorequation editor ft/s (4) lasting 0.01 seconds: -24.16 equation editorequation editor ft/s (b) find the instantaneous velocity when t=2