document.write( "Question 338999: I've heard that tossing a coin into a fountain will bring me good luck, so I throw a silver dollar up with a velocity of 5m/sec. and it falls into the fountain 1.3 meters below my hand. How long is the coin in the air?\r
\n" ); document.write( "\n" ); document.write( "In this question i just really dont understand how to do quadratic equations when you dont have the acceleration unless its -9.8m/s squared, but really not sure. \n" ); document.write( "
Algebra.Com's Answer #243041 by nerdybill(7384)\"\" \"About 
You can put this solution on YOUR website!
I've heard that tossing a coin into a fountain will bring me good luck, so I throw a silver dollar up with a velocity of 5m/sec. and it falls into the fountain 1.3 meters below my hand. How long is the coin in the air?
\n" ); document.write( "In this question i just really dont understand how to do quadratic equations when you dont have the acceleration unless its -9.8m/s squared, but really not sure.
\n" ); document.write( ".
\n" ); document.write( "Yes, gravity is your acceleration.
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\n" ); document.write( "Applying the equation of motion:
\n" ); document.write( "h(t) = (1/2)gt + vt + vo
\n" ); document.write( "where
\n" ); document.write( "h(t) is height
\n" ); document.write( "g is gravity
\n" ); document.write( "v is initial velocity
\n" ); document.write( "t is time
\n" ); document.write( "vo is the initial height
\n" ); document.write( ".
\n" ); document.write( "h(t) = (1/2)(-9.8)t + 5t + 1.3
\n" ); document.write( "h(t) = -4.6t + 5t + 1.3
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\n" ); document.write( "set h(t) to zero and solve for t:
\n" ); document.write( "0 = -4.6t + 5t + 1.3
\n" ); document.write( "applying quadratic formula we get:
\n" ); document.write( "t = {-0.217, 1.304}
\n" ); document.write( "we can throw out the negative solution leaving:
\n" ); document.write( "t = 1.3 seconds
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\n" ); document.write( "Details of quadratic to follow:
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"-4.6x%5E2%2B5x%2B1.3+=+0\") has the following solutons:
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\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
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\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
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\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%285%29%5E2-4%2A-4.6%2A1.3=48.92\".
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\n" ); document.write( " Discriminant d=48.92 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-5%2B-sqrt%28+48.92+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%285%29%2Bsqrt%28+48.92+%29%29%2F2%5C-4.6+=+-0.216769932610683\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%285%29-sqrt%28+48.92+%29%29%2F2%5C-4.6+=+1.30372645434981\"
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\n" ); document.write( " Quadratic expression \"-4.6x%5E2%2B5x%2B1.3\" can be factored:
\n" ); document.write( " \"-4.6x%5E2%2B5x%2B1.3+=+-4.6%28x--0.216769932610683%29%2A%28x-1.30372645434981%29\"
\n" ); document.write( " Again, the answer is: -0.216769932610683, 1.30372645434981.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-4.6%2Ax%5E2%2B5%2Ax%2B1.3+%29\"
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