document.write( "Question 763222: Wile E. Coyote is standing on a springboard atop a high cliff. Roadrunner drops a boulder on the other end of the springboard, sending Wile up with an initial velocity of 4ft/sec. At what time will he land in the river, 120 feet below the cliff? (h=-16t^2+VoT+S where Vo is the initial velocity, s is the initial height, and t is time) \n" ); document.write( "

Algebra.Com's Answer #464659 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
W.E.C. will land in the riven when $\"+h+=+0+\"$
\n" ); document.write( "when his height is zero
\n" ); document.write( " $\"+v%5B0%5D+=+4+\"$ ft/sec
\n" ); document.write( " $\"+s+=+120+\"$
\n" ); document.write( " $\"+h%28t%29+=+-16t%5E2+%2B+v%5B0%5D%2At+%2B+s+\"$
\n" ); document.write( " $\"+0+=+-16t%5E2+%2B+4t+%2B+120+\"$
\n" ); document.write( " $\"+0+=+-4t%5E2+%2B+t+%2B+30+\"$
\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( " $\"+b+=+4+\"$
\n" ); document.write( " $\"+c+=+30++\"$
\n" ); document.write( " $\"+t+=+%28+-1+%2B-+sqrt%28+1%5E2+-+4%2A%28-4%29%2A30+%29%29+%2F+%282%2A%28-4%29%29+\"$
\n" ); document.write( " $\"+t+=+%28+-1+%2B-+sqrt%28+1+%2B+480+%29%29+%2F+%28-8%29+\"$
\n" ); document.write( " $\"+t+=+%28+-1+-+sqrt%28+481+%29%29+%2F+%28-8%29+\"$
\n" ); document.write( " $\"+t+=+%28+-1+-+21.932%29+%2F+%28-8%29+\"$
\n" ); document.write( " $\"+t+=+-22.932+%2F+%28+-8+%29+=+2.866+\"$
\n" ); document.write( "In 2.866 sec, he lands in the river
\n" ); document.write( "Here's the plot:
\n" ); document.write( " $\"+graph%28+400%2C+400%2C+-1%2C+4%2C+-20%2C+140%2C+-16x%5E2+%2B+4x+%2B+120+%29+\"$
\n" ); document.write( "The time at $\"+h+=+0+\"$ looks about right
\n" ); document.write( " \n" ); document.write( "

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