document.write( "Question 472878: 1) A toy rocket is launched from ground level. its distance in feet from the ground in t seconds is given by.\r
\n" ); document.write( "\n" ); document.write( "s(t)= -16t^2+208t\r
\n" ); document.write( "\n" ); document.write( "Find the number of seconds required for the projectile to reach maximum height. What is the maximum height.\r
\n" ); document.write( "\n" ); document.write( "2) A washing machine can be filled in 8 minutes if both the hot and cold water taps are fully opened. Filling water with hot water alone takes 9 minutes longer than filling it with cold water alone. How long does it take to fill the washer with cold water? \n" ); document.write( "
Algebra.Com's Answer #324310 by ankor@dixie-net.com(22740)\"\" \"About 
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A toy rocket is launched from ground level. its distance in feet from the ground in t seconds is given by.
\n" ); document.write( "s(t)= -16t^2+208t
\n" ); document.write( "Find the number of seconds required for the projectile to reach maximum height.
\n" ); document.write( ":
\n" ); document.write( "Max height will be reached at the axis of symmetry, x = -b/(2a)
\n" ); document.write( "In this equation a=-16; b=208
\n" ); document.write( "t = \"%28-208%29%2F%282%2A-16%29\"
\n" ); document.write( "t = \"%28-208%29%2F%28-32%29\"
\n" ); document.write( "t = +6.5 sec to reach max height
\n" ); document.write( ":
\n" ); document.write( "What is the maximum height.
\n" ); document.write( "Find the max height by replacing t with 6.5
\n" ); document.write( "h = -16(6.5^2) + 208(6.5)
\n" ); document.write( "h = -676 + 1352
\n" ); document.write( "h = +676 ft is max height
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "2) A washing machine can be filled in 8 minutes if both the hot and cold water taps are fully opened.
\n" ); document.write( " Filling water with hot water alone takes 9 minutes longer than filling it with cold water alone.
\n" ); document.write( " How long does it take to fill the washer with cold water?
\n" ); document.write( ":
\n" ); document.write( "Let x = time required to fill the washer with cold water
\n" ); document.write( "then
\n" ); document.write( "(x+9) = time required to fill it with hot water
\n" ); document.write( "let a full washer = 1
\n" ); document.write( ";
\n" ); document.write( "\"8%2Fx\" + \"8%2F%28%28x%2B9%29%29\" = 1
\n" ); document.write( "multiply eq by x(x+9) to clear the denominators, results
\n" ); document.write( "8(x+9) + 8x = x(x+9)
\n" ); document.write( "8x + 72 + 8x = x^2 + 9x
\n" ); document.write( "arrange as a quadratic equation
\n" ); document.write( "x^2 + 9x - 16x - 72 = 0
\n" ); document.write( "x^2 - 7x - 72 = 0
\n" ); document.write( "Use the quadratic formula to find x, a=1, b=-7, c= -72
\n" ); document.write( "only the positive solution will make sense here \n" ); document.write( "
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