Question

A trampolinist steps off from 45 feet above ground to a trampoline 42 feet below. The function h(t) = -16t^2+45, where t represents the time in declines, gives the height h, in feet, of the trampolinist above the ground as he falls. When will the trampolinist land on the trampoline

Answer 1

at about t = 1.62

Explanation:

42 feet below a height of 45 feet is a height of 45-42 = 3 feet. You want to find t such that

h(t) = 3

-16t^2 +45 = 3

-16t^2 = -42 . . . . subtract 42

t^2 = -42/-16 = 21/8 . . . . . divide by -16

t = √2.625 ≈ 1.620 . . . . . take the square root

The trampolinist will land on the trampoline about 1.62 seconds after stepping off the platform.