document.write( "Question 153474: A stone is thrown into a well with an intial speed of 8 feet per second. The well is 80 feet deep. How long will it take for the stone to hit the bottom of the well? Use the equation d=vt+16t^2. where d=depth of the well, v= initial speed, and time\r
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\n" ); document.write( "2) 5/2
\n" ); document.write( "3) 2 or 5/2
\n" ); document.write( "4) none of these \n" ); document.write( "
Algebra.Com's Answer #112972 by stanbon(75887)\"\" \"About 
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A stone is thrown into a well with an intial speed of 8 feet per second. The well is 80 feet deep. How long will it take for the stone to hit the bottom of the well? Use the equation d=vt+16t^2. where d=depth of the well, v= initial speed, and time
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\n" ); document.write( "EQUATION:
\n" ); document.write( "d(t) = vt + 16t^2
\n" ); document.write( "80 = 8t + 16t^2
\n" ); document.write( "10 = t + 2t^2
\n" ); document.write( "2t^2 + t - 10 = 0
\n" ); document.write( "2t^2 + 5t - 4t - 10 = 0
\n" ); document.write( "t(2t+5) -2(2t+5) = 0
\n" ); document.write( "(2t+5)(t-2) = 0
\n" ); document.write( "Positive solution:
\n" ); document.write( "t = 2 seconds
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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\n" ); document.write( "choices:
\n" ); document.write( "1) 2
\n" ); document.write( "2) 5/2
\n" ); document.write( "3) 2 or 5/2
\n" ); document.write( "4) none of these
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