document.write( "Question 549675: If a stone is tossed from the top of a 190 meter building, the height of the stone as a function of time is given by h(t) = -9.8t^2 -10t +190, where t is in seconds, and height is in meters. After how many seconds will the stone hit the ground? Round to the nearest hundredth’s place; include units in your answer. \n" ); document.write( "

Algebra.Com's Answer #357947 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+h%28t%29+=+-9.8t%5E2+-10t+%2B190+\"$
\n" ); document.write( "Note that if I make $\"+t+=+0+\"$ , which is
\n" ); document.write( "when the stone is thrown from the
\n" ); document.write( "top of the building, I get $\"+190+\"$ ft as I should:
\n" ); document.write( " $\"+h%280%29+=+-9.8%2A0%5E2+-10%2A0+%2B190+\"$
\n" ); document.write( " $\"+h%280%29+=+190+\"$
\n" ); document.write( "The problem wants to know what is $\"t\"$
\n" ); document.write( "when $\"+h%28t%29+=+0+\"$ , or ground level.
\n" ); document.write( " $\"+0+=+-9.8t%5E2+-10t+%2B190+\"$
\n" ); document.write( "Use the quadratic formula
\n" ); document.write( " $\"t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"$
\n" ); document.write( " $\"+a+=+-9.8+\"$
\n" ); document.write( " $\"+b+=+-10+\"$
\n" ); document.write( " $\"+c+=+190+\"$
\n" ); document.write( "

\n" ); document.write( " $\"t+=+%28+10+%2B-+sqrt%28+100+%2B+4%2A%28-9.8%29%2A190+%29%29%2F%28-19.6%29%29+\"$
\n" ); document.write( " $\"t+=+%28+10+%2B-+sqrt%28+100+%2B+4%2A%28-9.8%29%2A190+%29%29%2F%28-19.6%29%29+\"$
\n" ); document.write( "I can't finish this because my cat, the Widster, just curled
\n" ); document.write( "up beside me, and I'm not going to disturb him to get a calculator.
\n" ); document.write( "But you get the idea. \n" ); document.write( "

\n" );