document.write( "Question 645947: How long would it take a ball dropped from the top of a 81 foot building to hit the ground? \r
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Algebra.Com's Answer #405672 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
You need to find $\"+h%28t%29+\"$ where $\"+h+\"$ is
\n" ); document.write( "the height above ground, and $\"t\"$ is the time in seconds
\n" ); document.write( "for the ball to hit the ground. The equation is:
\n" ); document.write( " $\"+h%28t%29+=+-16t%5E2+%2B+81+\"$
\n" ); document.write( "In words:
\n" ); document.write( "( height above ground ) = ( effect of gravity pulling down ) + ( starting height above ground )
\n" ); document.write( "Note that at $\"+t=0+\"$ when the ball hasn't started dropping yet
\n" ); document.write( " $\"+h%280%29+=+-16%2A%280%5E2%29+%2B+81+\"$
\n" ); document.write( " $\"+h%280%29+=+81+\"$ ft ,as it should be
\n" ); document.write( "----------------------------
\n" ); document.write( "When the ball hits the ground, the height is zero, so
\n" ); document.write( " $\"+0+=+-16t%5E2+%2B+81+\"$
\n" ); document.write( " $\"+16t%5E2+=+81+\"$
\n" ); document.write( " $\"+t%5E2+=+%28+9%2F4+%29%5E2+\"$
\n" ); document.write( " $\"+t+=+9%2F4+\"$ and
\n" ); document.write( " $\"+t+=+2.25+\"$ sec
\n" ); document.write( "It takes the ball 2.25 sec to hit the ground\r
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