document.write( "Question 32495: The Empire State Bldg is 1250 ft tall. If an object thrown upward from the top of the building at an initial velocity of 35 ft per second, its height after \"t\" seconds after it is thrown is given by the
\n" ); document.write( "function h(t)= -16t^2+35t+1250. How long will it be before the oject hits the ground? \n" ); document.write( "

Algebra.Com's Answer #19065 by Fermat(136) $\"\"$ $\"About$

You can put this solution on YOUR website!
h(t)= -16t^2+35t+1250
\n" ); document.write( "you have to find the time when h = 0 - that's when it hits the ground.
\n" ); document.write( "-16t^2+35t+1250 = 0
\n" ); document.write( "16t² - 35 - 1250 = 0
\n" ); document.write( "using the quadratic formula, $\"t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"$ , we get
\n" ); document.write( " $\"t+=+%2835+%2B-+sqrt%28+%28-35%29%5E2-4%2A%2816%29%2A%28-1250%29+%29%29%2F%282%2A16%29+\"$
\n" ); document.write( " $\"t+=+%2835+%2B-+sqrt%28+1225+%2B+80000%29+%29%2F%2832%29+\"$
\n" ); document.write( " $\"t+=+%2835+%2B-+285+%29%2F32+\"$
\n" ); document.write( " $\"t+=+320%2F32\"$ , $\"t+=+-250%2F32+\"$
\n" ); document.write( " $\"t=10\"$ , $\"t=-7.8125\"$
\n" ); document.write( "================== \n" ); document.write( "

\n" );