A beach ball rolls off a cliff and onto the beach. The height, in feet, of the beach ball can be modeled by the function h (t) = 64-16t2

h

(

t

)

=

64

-

16

t

2

, where t

t

represents time, in seconds.

What is the average rate of change in the height, in feet per second, during the first 1.25

1.25

seconds that the beach ball is in the air?

rate of change = - 32 feet/second

Step-by-step explanation:

h (t) = 64 - 16t2

t = time (seconds)

Look at the start of time where t = 0

h (t) = 64 - 16 * (0) * 2 = 64 feet

Then look at the specified time where t = 1.25 seconds

h (t) = 64 - 16 * (1.25sec) * 2 = 24 feet

rate of change = rate of change y / rate of change x

x = time, y = height

rate of change = (24 - 64) / (1.25 - 0) = - 32 feet/second