document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=792713>Question 792713</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A stone is projected vertically upwards and its height in meters after T seconds is given by h=50t-t^2. Find the time taken for the stone to first reach a height of 120meters.\r<BR>\n" );
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document.write( "I used the quadratic equation to find t but i didnt make it i got stuck when i used the cross method to find the factors, please help me...thankyou  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #480099 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=480099\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  A stone is projected vertically upwards and its height in meters after T seconds is given by h=50t-t^2. Find the time taken for the stone to first reach a height of 120meters<BR>\n" );
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document.write( "Solve:: 50t-t^2 = 120<BR>\n" );
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document.write( "t^2 - 50t + 120 = 0<BR>\n" );
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document.write( "t = [50 +- sqrt(2500-4*120)]/2<BR>\n" );
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document.write( "t = [50 +- sqrt(2020)]/2<BR>\n" );
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document.write( "t = [50 +- 44.94]/2<BR>\n" );
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document.write( "Smallest positive value of \"t\":<BR>\n" );
document.write( "t = 2.5278 seconds<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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