SOLUTION: an object is dropped from an initial height of s feet. the object's height at any time, t in seconds, is given by h=-16t(squared)+s. How long does it take for an object dropped fro

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Question 120158: an object is dropped from an initial height of s feet. the object's height at any time, t in seconds, is given by h=-16t(squared)+s. How long does it take for an object dropped from 300 feet to hit the ground?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
The initial height, s, is 300 feet, and the final height is 0, because you are concerned with the time it takes to hit the ground.

So, your equation becomes:

-16t%5E2%2B300=0

Add -300 to both sides and then multiply by -1:

16t%5E2=300

Take the square root of both sides:

4t=sqrt%28300%29 (you can ignore the negative square root because you are looking for a positive time value)

Divide by 4:

t=sqrt%2875%29

But 75=3%2A25, so sqrt%2875%29=5%2Asqrt%283%29

Hence, t=5%2Asqrt%283%29 seconds.

Hope this helps,
John