Question 949809: A stone thrown downward with an initial velocity of 29.4 m/sec will travel a distance of s meters, where s(t)=4.9t^2+29.4t and t is in seconds. if a stone is thrown downward at 29.4 m/sec from a height of 548.8m, how long will it take the stone to hit the ground?
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! A stone thrown downward with an initial velocity of 29.4 m/sec will travel a distance of s meters, where s(t)=4.9t^2+29.4t and t is in seconds. if a stone is thrown downward at 29.4 m/sec from a height of 548.8m, how long will it take the stone to hit the ground?
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Use the height measured from the ground.
h(t) = -4.9t^2 + 29.4t + 548.8
Notice at t = 0 seconds, h = 548.8 meters
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h(t) = -4.9t^2 + 29.4t + 548.8
When it hits the ground, h = 0
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-4.9t^2 + 29.4t + 548.8 = 0
t^2 - 6t - 112 = 0
Solve for t.
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