document.write( "Question 119148: Solving a science application. Suppose that a ball is thrown upward with an initial velocity of 80 ft/s. (the initial velocity is the speed with which the ball leaves the throwers hand. The spped will then decrease as the ball rises.) If the ball is released at a height of 77ft, the height equation may be written as follows: h= -16t^2+80t+5, round to the nearest hundredth of a second\r
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\n" ); document.write( "\n" ); document.write( "this is all i got, now I am lost, can someone please help me, thank you
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Algebra.Com's Answer #87253 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Do you want to solve for t?\r
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\n" ); document.write( "\n" ); document.write( "\"77=-16t%5E2%2B80t%2B5\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"0=-16t%5E2%2B80t%2B5-77\" Subtract 77 from both sides. \r
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\n" ); document.write( "\n" ); document.write( "\"0=-16t%5E2%2B80t-72\" Combine like terms\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for t:\r
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\n" ); document.write( "\n" ); document.write( "Starting with the general quadratic\r
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\n" ); document.write( "\n" ); document.write( "\"at%5E2%2Bbt%2Bc=0\"\r
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\n" ); document.write( "\n" ); document.write( "the general solution using the quadratic equation is:\r
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\n" ); document.write( "\n" ); document.write( "\"t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29\"\r
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\n" ); document.write( "\n" ); document.write( "So lets solve \"-16%2At%5E2%2B80%2At-72=0\" ( notice \"a=-16\", \"b=80\", and \"c=-72\")\r
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\n" ); document.write( "\n" ); document.write( "\"t+=+%28-80+%2B-+sqrt%28+%2880%29%5E2-4%2A-16%2A-72+%29%29%2F%282%2A-16%29\" Plug in a=-16, b=80, and c=-72\r
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\n" ); document.write( "\n" ); document.write( "\"t+=+%28-80+%2B-+sqrt%28+6400-4%2A-16%2A-72+%29%29%2F%282%2A-16%29\" Square 80 to get 6400 \r
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\n" ); document.write( "\n" ); document.write( "\"t+=+%28-80+%2B-+sqrt%28+6400%2B-4608+%29%29%2F%282%2A-16%29\" Multiply \"-4%2A-72%2A-16\" to get \"-4608\"\r
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\n" ); document.write( "\n" ); document.write( "\"t+=+%28-80+%2B-+sqrt%28+1792+%29%29%2F%282%2A-16%29\" Combine like terms in the radicand (everything under the square root)\r
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\n" ); document.write( "\n" ); document.write( "\"t+=+%28-80+%2B-+16%2Asqrt%287%29%29%2F%282%2A-16%29\" Simplify the square root (note: If you need help with simplifying the square root, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( "\"t+=+%28-80+%2B-+16%2Asqrt%287%29%29%2F-32\" Multiply 2 and -16 to get -32\r
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\n" ); document.write( "\n" ); document.write( "So now the expression breaks down into two parts\r
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\n" ); document.write( "\n" ); document.write( "\"t+=+%28-80+%2B+16%2Asqrt%287%29%29%2F-32\" or \"t+=+%28-80+-+16%2Asqrt%287%29%29%2F-32\"\r
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\n" ); document.write( "\n" ); document.write( "Now break up the fraction\r
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\n" ); document.write( "\n" ); document.write( "\"t=-80%2F-32%2B16%2Asqrt%287%29%2F-32\" or \"t=-80%2F-32-16%2Asqrt%287%29%2F-32\"\r
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\n" ); document.write( "\n" ); document.write( "Simplify\r
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\n" ); document.write( "\n" ); document.write( "\"t=5+%2F+2-sqrt%287%29%2F2\" or \"t=5+%2F+2%2Bsqrt%287%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "So these expressions approximate to\r
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\n" ); document.write( "\n" ); document.write( "\"t=1.1771243444677\" or \"t=3.8228756555323\"\r
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\n" ); document.write( "\n" ); document.write( "So our solutions are:\r
\n" ); document.write( "\n" ); document.write( "\"t=1.1771243444677\" or \"t=3.8228756555323\"\r
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\n" ); document.write( "\n" ); document.write( "So when the time is \"t=1.1771243444677\" or \"t=3.8228756555323\" the ball is at a height of 77 ft.\r
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