SOLUTION: Benjamin threw a rock straight up from a cliff that was 48 ft above the water. If the height of the rock h, in feet, after t seconds is given by the equation h=-16t^2+52t+48, how m

Question 1035819: Benjamin threw a rock straight up from a cliff that was 48 ft above the water. If the height of the rock h, in feet, after t seconds is given by the equation h=-16t^2+52t+48, how many seconds will it take for the rock to hit the water?
Found 2 solutions by josmiceli, ikleyn:
Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
The rock hits the water when

Divide both sides by

Use quadratic formula

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Note that I had to use the negative square root of
so that came out to be positive
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The rock takes 4 sec to hit the water
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Here's the plot:

Answer by ikleyn(52787)   (Show Source): You can put this solution on YOUR website!
.
Benjamin threw a rock straight up from a cliff that was 48 ft above the water. If the height of the rock h, in feet,
after t seconds is given by the equation h=-16t^2+52t+48, how many seconds will it take for the rock to hit the water?
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