Question

A hang glider pilot accidentally drops her compass from the top of a 400-foot cliff. The height h of the compass after t seconds is given by the quadratic equation h=−16t2+400. When will the compass hit the ground?

Answer 1

Answer:

5 seconds

Step-by-step explanation:

H= -16t2 + 400

Hit ground

H=0

0 = -16t2 + 400

0 = -16 ( t2 - 25)

-16

t2 -25 = 0

(t + 5)(t - 5) = 0

t + 5 = 0

- 5 -5

t = -5

t - 5 = 0

+ 5 +5

t = -5

t = 5

5 seconds to hit the ground