document.write( "Question 275417: A rock falls from a tower that is 304 feet high. As it is falling, its height is given by the formula h=304-16t^2. How many seconds(in tenths) will it take for the rock to hit the ground (h=0)? (I believe you just set H=0 and then solve? Is that correct?) \n" ); document.write( "

Algebra.Com's Answer #200889 by mananth(16946) $\"\"$ $\"About$

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A rock falls from a tower that is 304 feet high. As it is falling, its height is given by the formula h=304-16t^2. How many seconds(in tenths) will it take for the rock to hit the ground (h=0)? (I believe you just set H=0 and then solve? Is that correct?)\r
\n" ); document.write( "\n" ); document.write( "Yes\r
\n" ); document.write( "\n" ); document.write( "16t^2+h-304 =0\r
\n" ); document.write( "\n" ); document.write( "use the formula x1, x2 = -b (+, -) sqrt(b^2-4ac) / 2a\r
\n" ); document.write( "\n" ); document.write( "a=16, b=1 c=-304\r
\n" ); document.write( "\n" ); document.write( "b^2-4ac= 1-19456\r
\n" ); document.write( "\n" ); document.write( "= - 1 + sqrt( 19455) / 2*16\r
\n" ); document.write( "\n" ); document.write( "= -1+ 139.48 /32\r
\n" ); document.write( "\n" ); document.write( "= 138.48 /32
\n" ); document.write( "= 4.32 \r
\n" ); document.write( "\n" ); document.write( "Similarly find x2 and it will be -4.39\r
\n" ); document.write( "\n" ); document.write( "So t=4.32 seconds
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