If a ball is thrown in the air with a velocity42ft/s, its height in feettseconds later is given byy=42t16t².

(a) Find the average velocity for the time period beginning whent= 2 and lasting

(i)0.5 second.

ft/s

(ii)0.1 second.

ft/s

(iii)0.05 second.

ft/s

(iv)0.01 second.

ft/s

(b) Estimate the instantaneous velocity whent= 2.

ft/s