document.write( "Question 283805: A water rocket is launched upward with an initial velocity of 48 ft/sec. Its height h, in feet, after t seconds is given by h = 48t - 16t^2. After how many seconds will the height of the rocket be 20 feet? Show all steps necessary to arrive at your solution. \n" ); document.write( "
Algebra.Com's Answer #205984 by dabanfield(803)\"\" \"About 
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A water rocket is launched upward with an initial velocity of 48 ft/sec. Its height h, in feet, after t seconds is given by h = 48t - 16t^2. After how many seconds will the height of the rocket be 20 feet? Show all steps necessary to arrive at your solution.\r
\n" ); document.write( "\n" ); document.write( "We need to solve:\r
\n" ); document.write( "\n" ); document.write( "20 = 48t - 16t^2\r
\n" ); document.write( "\n" ); document.write( "or\r
\n" ); document.write( "\n" ); document.write( "16t^2 - 48t + 20 = 0\r
\n" ); document.write( "\n" ); document.write( "Divide both sides by 4;\r
\n" ); document.write( "\n" ); document.write( "4t^2 - 12t + 5 = 0\r
\n" ); document.write( "\n" ); document.write( "(2t - 1)*(2t - 5) = 0\r
\n" ); document.write( "\n" ); document.write( "Solutions are:\r
\n" ); document.write( "\n" ); document.write( "2t - 1 = 0 and 2t - 5 = 0 or\r
\n" ); document.write( "\n" ); document.write( "t = 1/2 and t = 5/2\r
\n" ); document.write( "\n" ); document.write( "The first time is on the way up and the second is on the way down.\r
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