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Question

At time t=0, a ball is thrown downward at 24 feet per second from a height of 160 feet above the ground. The equation h = -16t^2 - 24t +160 describes the height (in feet) of the ball. In how many seconds will the ball hit the ground? Express your answer as a decimal.

Accepted Answer

Setting h to zero, we find the following: align* 0& = -16t^2 - 24t + 160 & = 2t^2 +3t - 20 & = (2t-5)(t+4) align*The negative value of t is extraneous, so we are left with t=2.5