Question

A water balloon is tossed into the air with an upward velocity of 25 ft/s. Its height h(t) in ft after t seconds is given by the function h(t) = − 16t2 + 25t + 3. Show your work.

19. After how many seconds will the balloon hit the ground? (hint: Use the quadratic formula)

Answer 1

1.67 seconds

Explanation:

h(t) = − 16t^2 + 25t + 3

When it hits the ground h=0

0 = − 16t^2 + 25t + 3

Using the quadratic formula

-b ± sqrt(b^2 -4ac)

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2a

a = -16 b=25 c =3

Substituting what we know

-25 ± sqrt(25^2 -4(-16)3)

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2(-16)

-25 ± sqrt(625 +192)

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2(-16)

-25 ± sqrt(817)

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-32

-25 + sqrt(817) -25 - sqrt(817)

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-32 -32

-.112 1.67