SOLUTION: An angry construction worker throws his wrench downward from a height of 128 feet with an initial velocity of 32 feet per second. The height of the wrench above the ground after t

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Question 184005: An angry construction worker throws his wrench downward from a height of 128 feet with an initial velocity of 32 feet per second. The height of the wrench above the ground after t seconds is given by
S(t)= -16t^-32t+128
A)What is the height of the wrench after 1 second?
B)How long does it take for the wrench to reach the ground?
Found 2 solutions by solver91311, stanbon:
Answer by solver91311(24713) (Show Source):
You can put this solution on YOUR website!

Part (A): Substitute 1 for t and then do the arithmetic.

Part (B): Set the function expression equal to zero.

Multiply by :

Solve the quadratic by factoring. Exclude the extraneous negative root. The positive root is the answer.

John

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
S(t)= -16t^2-32t+128
A)What is the height of the wrench after 1 second?
s(1) = -16-32+128 = 80 ft
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B)How long does it take for the wrench to reach the ground?
Height is zero when the wrench is on the ground.
-16t^2-32t+128 = 0
Divide thru by -16 to get:
t^2 + 2t - 8 = 0
Factor:
(t+4)(t-2) = 0
Positive solution:
t = 2 seconds
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Cheers,
Stan H.