Algebra.Com's Answer #145025 by nerdybill(7384)![\"\"](\"/images/stars/stars-13.gif\")  
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An object that is projected straight downward with initial velocity of v feet per second is at a height from ground  , where s = initial height in feet, and t = time in seconds. If Bianca is standing on a ledge 46.75 feet above the ground and throws a penny straight down with an initial velocity of 12 feet per second, in how many seconds will it reach the ground?
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document.write( "The problem gives you:
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document.write( "s (initial height) as 46.75 feet
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document.write( "v (initial velocity) as 12 feet/sec
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document.write( "Since they want to know when it will reach the ground -- h (height) would be 0.
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document.write( "So, set h = 0 and solve for 't':
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document.write( "Since we can't factor, use the quadratic equation to solve. Doing so yields:
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document.write( "t={-2.125, 1.375}
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document.write( "Throw out the negative solution -- this leaves:
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document.write( "t = 1.375 seconds
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document.write( "Details of quadratic follows:
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document.write( " | Solved by pluggable solver: SOLVE quadratic equation with variable | \n" );
document.write( "Quadratic equation  (in our case  ) has the following solutons:
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document.write( " For these solutions to exist, the discriminant  should not be a negative number.
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document.write( " First, we need to compute the discriminant :  .
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document.write( " Discriminant d=3136 is greater than zero. That means that there are two solutions:  .
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document.write( " Quadratic expression  can be factored:
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document.write( " Again, the answer is: -2.125, 1.375.\n" );
document.write( "Here's your graph:
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