Question

or
Tower Escape is one of the most popular thrill rides at Mountain Adventure amusement park. It lifts riders to the top of a tower and drops them from a height of 200 feet. The riders fall to a height of 75 feet, at which point magnetic brakes slow them down.
Which equation can you use to find how many seconds the riders fall before slowing down?
If an object falls from s feet above the ground, the object's height in feet, h, after t seconds can be modeled by the formula h=
–
16t2+s.
To the nearest tenth of a second, how long do the riders fall before slowing down?

Answer 1

Use h = -16t^2 + s with s = 200 and h = 75:
75 = -16t^2 + 200.

Solve:
16t^2 = 200 − 75 = 125
t^2 = 125/16 = 7.8125
t = sqrt(7.8125) ≈ 2.795 s.

To the nearest tenth, the riders fall for 2.8 seconds.