document.write( "Question 369002: Lewis Tower in Philadelphia is 400 ft. high. Suppose that a ball is projected upward from the top of the tower, and its position in feet above the ground is given by the quadratic function defined by f(t)= -16t^2+45t+400, where t is the number of seconds elapsed. How long to the nearest 10th of a second will it take for the ball to reach a height of 200 ft. above the ground?\r
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Algebra.Com's Answer #262966 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi,
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document.write( "position in feet above the ground  =  -16t^2+45t+400
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document.write( "How long will it take for the ball to reach a height of 200 ft. above the ground
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document.write( "200 = -16t^2+45t+400
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document.write( "16t^2 - 45t - 200 = 0
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document.write( " Note: solution t < 0 cannot use
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document.write( "t = 166.8 /32 = 5.2 sec \n" );
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