A small toy rocket is launched from a 20-foot pad. The height (h, in feet) of the rocket t seconds after

taking off is given by the formula h = - 2t^2 - 6t + 20. How long will it take the rocket to hit the

ground?

Question

Mathematics

Gwendolyn

10 September, 13:17

A small toy rocket is launched from a 20-foot pad. The height (h, in feet) of the rocket t seconds after

taking off is given by the formula h = - 2t^2 - 6t + 20. How long will it take the rocket to hit the

ground?

+3

Answers (1)

Know the Answer?

Franklin Stevenson · Answer 1

t = 2 sec

Step-by-step explanation:

h = - 2t² - 6t + 20

When the rocket hits the ground. h = 0 ft.

- 2t² - 6t + 20 = 0 / : (-2)

t² + 3t - 10 = 0

(t + 5) (t - 2) = 0

t = - 5, t = 2

Time can be only positive.

A small toy rocket is launched from a 20-foot pad. The height (h, in feet) of the rocket t seconds aftertaking off is given by the formula h = - 2t^2 - 6t + 20. How long will it take the rocket to hit theground?

A small toy rocket is launched from a 20-foot pad. The height (h, in feet) of the rocket t seconds after

taking off is given by the formula h = - 2t^2 - 6t + 20. How long will it take the rocket to hit the

ground?