<PRE><B>Question 544765</B>
a ball is thrown straight up from a rooftop 240ft high. The ball misses the rooftop on the way down.When will the ball be at 120 ft. identify solution on a graph   h=-16t^2+56t+240
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The 56 is the speed of the upward throw, 56 ft/sec
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h=-16t^2+56t+240
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Solve: -16t^2+56t+240 = 120
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-2t^2 + 7t + 15 = 0
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*[invoke solve_quadratic_equation -2,7,15]
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Ignore the negative solution.
t = 5 seconds
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