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12 votes
12 votes
An observation deck extends 118 feet out above a valley. The deck sits 68 feet above the valley floor. If an object is dropped from the obseh in feet, after t seconds, is given by h = - 16t2 + 68. How long will it take for the object to be 4 feet above the valley floor?It will take seconds for the object to be 4 feet above the valley floor.(Type an integer or a decimal.)Help Me Solve ThisView an ExampleGet More HelpClear All

User Snapper
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1 Answer

16 votes
16 votes

The function that describes the height is

h= -16t²+68.

As we know from the question, when t=0, h=68.

h=4, we'll have:

4=-16t² + 68

-16t² = -64

t² = 64/16

t²=4

t=2

It will take 2 seconds for the object to be 4 feet above the valley floor.

User Doov
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