document.write( "Question 1159585: Please help me solve this question\r
\n" ); document.write( "\n" ); document.write( "When a ball is thrown or kicked, the path it travels is shaped like a parabola. Suppose a soccer ball is kicked from ground level, reaches a maximum height of 25 feet , and hits the ground 100ft from where it was kicked. Assuming that the ball was kicked out the origin. Write an equation of the parabola that models the flight of the ball. \n" ); document.write( "

Algebra.Com's Answer #782640 by ikleyn(52794) $\"\"$ $\"About$

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document.write( "The parabola is opened down --- it means that the leading coefficient at the quadratic term is negative.\r\n" );
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document.write( "The zero level is at x= 0 and x= 100 feet.  Hence, the parabola has the form\r\n" );
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document.write( "    y(x) = a*x*(x-100)\r\n" );
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document.write( "with the unknown coefficient \"a\".  We know that y= 25 at x= 50 (half way from x= 0 to x= 100), so\r\n" );
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document.write( "    25 = a*50*(100-50) = a*50*(-50).\r\n" );
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document.write( "It gives\r\n" );
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document.write( "    a = -  = - .\r\n" );
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document.write( "Thus the final equation of the parabola is  \r\n" );
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document.write( "    y(x) = -0.01*x*(x-100).\r\n" );
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document.write( "You can transform it to any other equivalent form.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved, answered, explained and completed.\r
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