document.write( "Question 820460: a ball is thrown straight upward at an initial speed of 240 feet per second. From physics, we know that the ball will reach a height of h feet after t seconds where h and t are related by the following formula: h=-16t^2+240t. when did the ball hit the ground? \n" ); document.write( "
Algebra.Com's Answer #493550 by TimothyLamb(4379)\"\" \"About 
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h = -16t^2 + 240t
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\n" ); document.write( "the above quadratic equation is in standard form, with a=-16, b=240, and c=0
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\n" ); document.write( "to solve the quadratic equation, by using the quadratic formula, plug this:
\n" ); document.write( "-16 240 0
\n" ); document.write( "into this: https://sooeet.com/math/quadratic-equation-solver.php
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\n" ); document.write( "the two real roots (i.e. the two x-intercepts), of the quadratic are:
\n" ); document.write( "t = 0
\n" ); document.write( "t = 15
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\n" ); document.write( "answer:
\n" ); document.write( "ball hits the ground 15 seconds after being thrown
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