document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=388759>Question 388759</A>: <I><SPAN STYLE=\"word-break: break-all;\"> There is 1.5 L of water in a kettle on a cooking plate of 2.0 KW. It takes 7 minutes to heat the water from 20 C to the poiling point.<BR>\n" );
document.write( "a) How much electrical energy is required ? <BR>\n" );
document.write( "b) What is the efficiency of the heating process?! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #275148 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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/cgi-bin/show-face.mpl?user=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=275148\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1.5 liters = 1500 grams of water<BR>\n" );
document.write( "1500 gm * (100 - 20ºC) = 1.2E5 calories<BR>\n" );
document.write( "1 watt-min = 14.33 calories<BR>\n" );
document.write( "1.2E5/14.33 = 8374 watt-minutes to heat the water<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "2000 watts * 7 minw = 14000 watt-minutes<BR>\n" );
document.write( "e = 8374/14000 = 0.5981<BR>\n" );
document.write( "e =~ 60%<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );