Question 179248
s(t)=-16t^2-32t+128
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a) simply plug substitute 1 for a t and solve:
s(t)=-16t^2-32t+128
s(1)=-16(1)^2-32(1)+128
s(1)=-16-32+128
s(1)=-48+128
s(1)= 80 feet
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b) substitute 0 for s(t) and solve for t:
s(t)=-16t^2-32t+128
0=-16t^2-32t+128
Divide both sides by -16:
0=t^2+2t-8
Factor:
0=(t+4)(t-2)
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t = {-4,2}
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Toss out the negative solution leaves with:
time for wrench to reach ground = 2 seconds