document.write( "Question 79393: Please help with solving this problem--I'm lost.\r
\n" ); document.write( "\n" ); document.write( "When a ball is thrown, its height in feet h after t seconds is given by the equation h=vt-16t, where v is the initial upwards velocity in feet per second. If v=36 feet per second, find all values of t for which h=19 feet. Do not round any intermediate steps. Round your answers to 2 decimal places.\r
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Algebra.Com's Answer #56978 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
When a ball is thrown, its height in feet h after t seconds is given by the equation h=vt-16t, where v is the initial upwards velocity in feet per second. If v=36 feet per second, find all values of t for which h=19 feet. Do not round any intermediate steps. Round your answers to 2 decimal places.
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\n" ); document.write( "I think the equations would be: -16t^2 + 36t = 19
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\n" ); document.write( "-16t^2 + 36t - 19 = 0
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\n" ); document.write( "Find the value of t using the quadratic formula: a=-16; b=36; c=-19
\n" ); document.write( "\"t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"
\n" ); document.write( ":
\n" ); document.write( "\"t+=+%28-36+%2B-+sqrt%28+36%5E2+-+4%2A-16%2A-19+%29%29%2F%282%2A-16%29+\"
\n" ); document.write( ":
\n" ); document.write( "\"t+=+%28-36+%2B-+sqrt%281296+-+1216+%29%29%2F%28-32%29+\"
\n" ); document.write( ":
\n" ); document.write( "\"t+=+%28-36+%2B-+sqrt%2880+%29%29%2F%28-32%29+\"
\n" ); document.write( ":
\n" ); document.write( "Two solutions:
\n" ); document.write( "\"t+=+%28-36+%2B+8.94%29%2F-32\"
\n" ); document.write( "\"t+=+%28-27.06%29%2F%28-32%29\"
\n" ); document.write( "t = +.85 sec (At 19' on the way up)
\n" ); document.write( "and
\n" ); document.write( "\"t+=+%28-36+-+8.94%29%2F-32\"
\n" ); document.write( "\"t+=+%28-44.94%29%2F%28-32%29\"
\n" ); document.write( "t = 1.40 sec (At 19' on the way down)
\n" ); document.write( ":
\n" ); document.write( "Would look like this:
\n" ); document.write( "\"+graph%28+300%2C+200%2C+-2%2C+4%2C+-5%2C+30%2C+-16x%5E2+%2B+36x+%29+\"
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\n" ); document.write( "Note that it shows about 19 ft at about .85 sec and 1.4 sec
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\n" ); document.write( "Has this helped you find your way? \r
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