Question

Samantha threw an apple out of a window from the tenth floor of her apartment building. The equation y = -16t2 + 120 can be used to represent the fruit's height above the ground, where t represents time, after she thew the apple. How long did it take the apple to hit the ground? Round your answer to the nearest hundredth.

Answer 1

2.74

Explanation:

The height of the apple when it hits the ground is zero

Equate to zero and solve for t

- 16t² + 120 = 0 ( subtract 120 from both sides )

- 16t² = - 120 ( divide both sides by - 16 )

t² = 7.5 ( take the square root of both sides )

t =
`√(7.5)` ≈ 2.74