Question

Quicklkkkkkkkk If a football player passes a football from 4 feet off the ground with an initial velocity of 36 feet per second, how long will it take the football to hit the ground? Use the equation h = −16t2 + 6t + 4. Round your answer to the nearest hundredth. 0.72 0.65 0.35 0.27

Answer 1

.72

Explanation:

I got it right on the test!!!

Answer 2

Since time can't be negative, the only possible solution is 0.72 s.

Explanation:

When the ball hits the ground its height is equal to 0, so we must find a value for "t" that results in h = 0. We have:

`-16*t^2 + 6*t + 4 = 0\\t_(1,2) = (-6 \pm √((6)^2 - 4*(-16)*(4)))/(2*(-16))\\t_(1,2) = (-6 \pm √(292))/(-32)\\t_(1,2) = (-6 \pm 17.1)/(-32)\\t_1 = (-6 -17.1)/(-32) = 0.72\\t_2 = (-6 + 17.1)/(-32) = -0.35\\`

Since time can't be negative, the only possible solution is 0.72 s.