Part a: Option D 18 feet per second
Part b: increasing
Solution:
Height
Part a: To find the average rate of change for h(t) between t = 0 and t = 2.
Substitute t = 0 in h(t).
h(0) = 3
Substitute t = 2 in h(t).
h(2) = 39
Average rate of change formula:
Here, a = 0 and b = 2.
= 18
Average rate of change = 18 feet per second
Option D is the correct answer.
Part b:
This means height of the ball is increasing for 0 < x < 2.