## The height of a ball thrown into the air after t seconds have elapsed is h = −16t2 + 40t + 6 feet. What is the first time, t, when the ball

Question

The height of a ball thrown into the air after t seconds have elapsed is h = −16t2 + 40t + 6 feet. What is the first time, t, when the ball will reach a height of 20 feet? Round your answer to two decimal places.

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2021-11-25T13:06:38+00:00
2021-11-25T13:06:38+00:00 1 Answer
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## Answers ( )

## The first time when the ball will reach a height of 20 feet is 0.42 seconds

Solution:Given that,

The height of a ball thrown into the air after t seconds have elapsed is:What is the first time, t, when the ball will reach a height of 20 feet?Substitute h = 20

Solve by quadractic formulaRounding off we get,

t = 2.08 , t = 0.42Thus the first time when the ball will reach a height of 20 feet is 0.42 seconds