document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1190583>Question 1190583</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An elevator has a mass of 1500 kg and is carrying 10 passengers through a height of <BR>\n" );
document.write( "15 m from the ground. The time taken to lift the elevator to that height is 0.75 minutes. <BR>\n" );
document.write( "Calculate the power required by the motor to lift the elevator if the mass per passenger <BR>\n" );
document.write( "is 50 kg.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #822284 by </B><A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><B>math_tutor2020(3817)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><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=822284\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=black size=3><BR>\n" );
document.write( "0.75 minutes = 60*0.75 = 45 seconds\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "1 passenger = 50 kg<BR>\n" );
document.write( "10*1 passenger = 10*50 kg<BR>\n" );
document.write( "10 passengers = 500 kg<BR>\n" );
document.write( "Add on the mass of the elevator itself<BR>\n" );
document.write( "500+1500 = 2000 kg\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "The force of gravity is pulling down on the 2000 kg combined mass at an acceleration of roughly 9.81 m/s^2<BR>\n" );
document.write( "Force = Mass*acceleration<BR>\n" );
document.write( "F = ma<BR>\n" );
document.write( "F = 2000*9.81<BR>\n" );
document.write( "F = 19,620 newtons<BR>\n" );
document.write( "This is approximate the upward force needed to counterbalance the force of gravity, so that the system moves upward.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Work = Force*Displacement<BR>\n" );
document.write( "Work = (19,620 newtons)*(15 meters)<BR>\n" );
document.write( "Work = 294,300 newton meters<BR>\n" );
document.write( "Work = 294,300 joules\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "power = (amount of work done)/(change in time)<BR>\n" );
document.write( "power = (294,300 joules)/(45 seconds)<BR>\n" );
document.write( "power = 6540 joules per second<BR>\n" );
document.write( "power = 6540 watts\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Answer: <font color=red>6540 watts</font> (approximate)<BR>\n" );
document.write( "</font> </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );