document.write( "Question 389336: a man jumps off a cliff into water, given the function h(t) = -16t^2+16t+480 where t = time in seconds and h = height in feet At what height did the man jump? What was the the highest point he reached? and how many secs did he take to hit the water?
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Algebra.Com's Answer #275910 by robertb(5830) $\"\"$ $\"About$

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The man jumped off the cliff at 480 feet (The height of the cliff, when t = 0.)
\n" ); document.write( "The highest point reached is $\"%284ac+-+b%5E2%29%2F%284a%29+=+%284%2A-16%2A480+-+256%29%2F%28-64%29+=+484\"$ feet. (Or 4 feet above cliff level.)
\n" ); document.write( "To find the length of time it took him to hit the water, solve for t in
\n" ); document.write( " $\"0+=+-16t%5E2+%2B+16t+%2B+480\"$ ;
\n" ); document.write( " $\"0+=+t%5E2+-+t+-+30\"$ ;
\n" ); document.write( "(t-6)(t+5) = 0
\n" ); document.write( "The man will hit the water after 6 seconds. (Eliminate the negative value of t.) \n" ); document.write( "

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