<PRE><B>Question 113224</B>
A ball is thrown downward from a window in a tall building. Its position at time T in seconds is s=16t^2+32t, where S is in feet. How long (to the nearest tenth) will it take the ball to fall 276 feet?
:
The equation:
16t^2 + 32t = 276
:
16t^2 + 32t - 276 = 0
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Simplify, divide equation by 4
4t^2 + 8t - 69 = 0
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Find t using the quadratic formula: a = 4; b = 8; c = -69
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{{{t = (-8 +- sqrt(8^2 - 4 * 4* -69 ))/(2*4) }}}
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Solve this and the positive solution should be: t = 3.272 </PRE>