A football is kicked into the air from the initial height of 3 ft. The height, in feet, of the football above the ground is given by s(t) = -16t² + 35t + 3, where t is time in seconds and t > 0. Which is closest to the time when the football will be 20 ft above ground?

Solution:

Given,

s = height

t = time.

Since we have the height, we can solve it as,

20 = -16t² + 35t + 3

-16t² + 35t + 3 - 20 = 0

-16t² + 35t - 17 = 0

Using quadratic formula we get,

t = 35 - √137/32.

t = √137 + 35/32.

t ≈ 1.459

t ≈ 0.727

Therefore, the closest time when the football will be 20 ft above ground is t ≈ 0.727 to t ≈ 1.459

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A football is kicked into the air from the initial height of 3 ft. The height, in feet, of the football above the ground is given by s(t) = -16t² + 35t + 3, where t is time in seconds and t > 0. Which is closest to the time when the football will be 20 ft above ground?

Summary:

A football is kicked into the air from the initial height of 3 ft. The height, in feet, of the football above the ground is given by s(t) = -16t² + 35t + 3, where t is time in seconds and t > 0. The closest time when the football will be 20 ft above ground is t ≈ 0.727 to t ≈ 1.459