The height h (in feet) of a kangaroo's jump can be modeled by h = – 16t 2 + 18t where t is the time (in seconds) since the kangaroo jumped off of the ground.

Question

How long was the kangaroo in the air?

Answer 1

set h=0, solve for t

-16t^2 + 18t = 0

-8t + 9 + 0

8t = 9

t = 9/8 = 1.125 seconds to go from blast off to hit the ground