document.write( "Question 1116293: A model rocket is launched with an initial upward velocity of
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Algebra.Com's Answer #731185 by ikleyn(52781) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "The correct equation is (and must be !) \r\n" );
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document.write( "h(t) = -5t^2 + 60t.\r\n" );
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document.write( "To answer the question, you need to solve the equation  h(t) = 27,  which is the same as\r\n" );
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document.write( "-5t^2 + 60t = 27,\r\n" );
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document.write( "5t^2 - 60t + 27 = 0.\r\n" );
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document.write( "Solve it using the quadratic formula.\r\n" );
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document.write( "You will get two real positive roots.\r\n" );
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document.write( "One root is the time for  h(t) = 27 m  flying up;  the other root is the time for  h(t) = 27 m  falling down.\r\n" );
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document.write( "Plot h(t) = -5t^2 + 60t (red) and y = 27 (green)\r\n" );
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