document.write( "Question 517795: A ball is thrown straight up with an initial velocity of 80 feet per second from the top of a building 23 feet tall. It's height h (in feet) above the ground t seconds after the ball is thrown is given by h = -16t^2 + 80t + 23. When will the ball be 119 feet above the ground for the first time?\r
\n" ); document.write( "\n" ); document.write( "*** ^2 stands for squared or to the second power ***
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Algebra.Com's Answer #344937 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
The ball will probably be 119' above the ground twice:
\n" ); document.write( "once going up and again coming down.
\n" ); document.write( "Just pick the smallest value for \"t\" and that will
\n" ); document.write( "be going up.
\n" ); document.write( "\"+h+=+-16t%5E2+%2B+80t+%2B+23+\"
\n" ); document.write( "\"+119+=+-16t%5E2+%2B+80t+%2B+23+\"
\n" ); document.write( "\"+-16t%5E2+%2B+80t+%2B+23+-+119+=+0+\"
\n" ); document.write( "\"+-16t%5E2+%2B+80t+-+96+=+0+\"
\n" ); document.write( "\"+-t%5E2+%2B+5t+-+6+=+0+\"
\n" ); document.write( "Use quadratic formula
\n" ); document.write( "\"+t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"
\n" ); document.write( "\"+a=+-1+\"
\n" ); document.write( "\"+b+=+5+\"
\n" ); document.write( "\"+c+=+-6+\"
\n" ); document.write( "\"+t+=+%28-5+%2B-+sqrt%28+5%5E2+-+4%2A%28-1%29%2A%28-6%29+%29%29%2F%282%2A%28-1%29%29+\"
\n" ); document.write( "\"+t+=+%28-5+%2B-+sqrt%28+25+-+24+%29%29%2F%28-2%29+\"
\n" ); document.write( "\"+t+=+%28+-5+%2B+1+%29+%2F+%28-2%29+\"
\n" ); document.write( "\"+t+=+2+\"
\n" ); document.write( "and, also,
\n" ); document.write( "\"+t+=+%28+-5+-+1%29+%2F+%28-2%29+\"
\n" ); document.write( "\"+t+=+3+\"
\n" ); document.write( "2 sec from when the ball is thrown, the
\n" ); document.write( "height will be 119' above ground for the first time.
\n" ); document.write( "check:
\n" ); document.write( "\"+119+=+-16t%5E2+%2B+80t+%2B+23+\"
\n" ); document.write( "\"+119+=-16%2A4+%2B+80%2A2+%2B+23+\"
\n" ); document.write( "\"+119+=+-64+%2B+160+%2B+23+\"
\n" ); document.write( "\"+119+=+96+%2B+23+\"
\n" ); document.write( "\"+119+=+119+\"
\n" ); document.write( "OK
\n" ); document.write( "Here's a plot:
\n" ); document.write( "\"+graph%28+400%2C+400%2C+-1%2C+6%2C+-10%2C+130%2C+-16x%5E2+%2B+80x+%2B+23+%29+\"
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