A graphing calculator is recommended. If a ball is thrown into the air with an initial velocity of 50 ft/s, its height in feet after t seconds is given by y = 50t - 16t2. (a) Find the average velocity of the ball (in ft/s) for the time interval beginning at t 2 and lasting for each of the following. (i) 0.5 seconds ft/s (ii) 0.1 seconds ft/s (iii) 0.05 seconds ft/s (iv) 0.01 seconds ft/s 1 (b) Use your answers from part (a) to estimate the instantaneous velocity (in ft/s) when t = 2. ft/s