document.write( "Question 431119: A rock is thrown from the top of a tall building. The distance d, in feet, between the rock and the ground t seconds after it is thrown is given by
\n" ); document.write( "d= -16t^2-4t+432. How long after the rock is thrown is it 300 feet from the ground? \n" ); document.write( "

Algebra.Com's Answer #299288 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+d=+-16t%5E2+-+4t+%2B+432+\"$
\n" ); document.write( " $\"+300+=+-16t%5E2+-4t+%2B+432+\"$
\n" ); document.write( " $\"+-16t%5E2+-+4t+=+-+132+\"$
\n" ); document.write( " $\"+16t%5E2+%2B+4t+-+132+=+0+\"$
\n" ); document.write( " $\"++4t%5E2+%2B+t+-+33+=+0+\"$
\n" ); document.write( " $\"+t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"$
\n" ); document.write( " $\"+a+=+4+\"$
\n" ); document.write( " $\"+b+=+1+\"$
\n" ); document.write( " $\"+c+=+-33+\"$
\n" ); document.write( " $\"+t+=+%28-1+%2B-+sqrt%28+1%5E2-4%2A4%2A%28-33%29+%29%29%2F%282%2A4%29+\"$
\n" ); document.write( " $\"+t+=+%28-1+%2B-+sqrt%28+1++%2B+528+%29%29+%2F+8+\"$
\n" ); document.write( " $\"+t+=+%28-1+%2B-+23%29+%2F+8+\"$
\n" ); document.write( " $\"+t+=+-3+\"$ (can't use this)
\n" ); document.write( " $\"+t+=+11%2F4+\"$
\n" ); document.write( "The rock is 300 ft from the ground
\n" ); document.write( "when t = 2.75 sec \n" ); document.write( "

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