document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=80218>Question 80218</A>: <I><SPAN STYLE=\"word-break: break-all;\"> APPLICATIONS OF FACTORING<BR>\n" );
document.write( "use the formula,     h= rt - 4.9t^2\r<BR>\n" );
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document.write( "In howmany seconds after it is thrown upward from the ground with an initial speed of 34.3m/s will the object be 49m above the ground?<BR>\n" );
document.write( " Could you explain this please? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #57559 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=57559\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> h(t) = rt - 4.9t^2\r<BR>\n" );
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document.write( "In how many seconds after it is thrown upward from the ground with an initial<BR>\n" );
document.write( "speed of 34.3m/s will the object be 49m above the ground? <BR>\n" );
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document.write( "h(t) is the height in meters of the object at time \"t\" seconds.<BR>\n" );
document.write( "r is the initial velocity of the object(r=34.3 meters/sec).<BR>\n" );
document.write( "-4.9 is (1/2)g where g is the acceleration of the object due to gravity.<BR>\n" );
document.write( "Your formula assumes the object started up from ground level.<BR>\n" );
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document.write( "Your problem: Substitute to get:<BR>\n" );
document.write( "49 = 34.3t-4.9t^2<BR>\n" );
document.write( "Rearrange to get:<BR>\n" );
document.write( "4.9t^2-34.3t+49=0<BR>\n" );
document.write( "Solve for t:<BR>\n" );
document.write( "t=[34.3+-sqrt(34.3^2-4*4.9*49]/{2*4.9)<BR>\n" );
document.write( "t=35.8 seconds or t=32.8 seconds<BR>\n" );
document.write( "The object will be at 49 meters first at t=32.8 seconds then at 35.8 seconds.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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