Answer:
a) h = 0.1: 
, h = 0.01: 
, h = 0.001: 
, b) The instantaneous velocity of the ball when 
is 
feet per second.
Step-by-step explanation:
a) We know that 
describes the position of the ball, measured in feet, in time, measured in seconds, and the average velocity (
), measured in feet per second, can be done by means of the following definition:
Where:
- Position of the ball evaluated at , measured in feet.
- Position of the ball evaluated at 
, measured in feet.
- Change interval, measured in seconds.
Now, we obtained different average velocities by means of different change intervals:
b) The instantaneous velocity when can be obtained by using the following limit:
And we finally evaluate the instantaneous velocity at :
The instantaneous velocity of the ball when is feet per second.
