document.write( "Question 774213: the height \"h\" of a rock, \"t\" seconds after it is dropped off a cliff is given by the equation: h=-16t(squared)+256. How many seconds after the rock is dropped will it hit the ground? \n" ); document.write( "

Algebra.Com's Answer #472106 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+h+=+-16t%5E2+%2B+256+\"$
\n" ); document.write( "You know it is being dropped from a cliff
\n" ); document.write( "that is $\"+256+\"$ ft high, because at
\n" ); document.write( " $\"+t+=+0+\"$ , $\"+h+=+256+\"$
\n" ); document.write( "----------------------
\n" ); document.write( "The $\"+-16t%5E2+\"$ term tells you what
\n" ); document.write( "gravity is doing to the rock as the
\n" ); document.write( "seconds go by
\n" ); document.write( "----------------------
\n" ); document.write( "It will hit the ground when $\"+h+=+0+\"$ , so
\n" ); document.write( " $\"+0+=+-16t%5E2+%2B+256+\"$
\n" ); document.write( " $\"+16t%5E2+=+256+\"$
\n" ); document.write( " $\"+16t%5E2+=+16%5E2+\"$
\n" ); document.write( " $\"+t%5E2+=+16+\"$
\n" ); document.write( " $\"+t+=+4+\"$
\n" ); document.write( "In 4 seconds the rock will hit the ground
\n" ); document.write( "Here's what the plot looks like:
\n" ); document.write( " $\"+graph%28+400%2C+400%2C+-2%2C+6%2C+-30%2C+300%2C+-16x%5E2+%2B+256+%29+\"$
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