document.write( "Question 1144482: A ball thrown from a height of 1 meter with an initial upward velocity of 25 m/s. The balls height h (in meters) after t seconds is given by the following h=1+25t-5t^2 . Find all values of t for which the balls height is 11 meters. Round to the nearest hundredth \n" ); document.write( "

Algebra.Com's Answer #765623 by ikleyn(52788) $\"\"$ $\"About$

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document.write( "The ball is at the height 11 meters, when\r\n" );
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document.write( "    1 + 25t - 5t^2 = 11   meters.\r\n" );
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document.write( "Solve this quadratic equation to find \"t\".\r\n" );
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document.write( "    5t^2 - 25t + 10 = 0\r\n" );
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document.write( "      t^2 - 5t + 2 = 0\r\n" );
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document.write( "       =  = \r\n" );
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document.write( "       =  = 0.44 seconds (approximately),   and\r\n" );
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document.write( "       =  = 4.56 seconds (approximately).\r\n" );
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document.write( "   \r\n" );
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document.write( "    Plot y =  (red) and y = 11 (green)\r\n" );
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document.write( "Time moment   corresponds to the ball moving up.\r\n" );
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document.write( "Time moment   corresponds to the ball falling down.\r\n" );
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