document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1187491>Question 1187491</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An object accelerates from rest at 3 m/s2 to the right with a net force of 280 N.  Calculate the mass of the object and the distance it travels in 5 seconds. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #818721 by </B><A HREF=/tutors/aboutme.mpl?userid=KMST><B>KMST(5328)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=KMST><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=KMST><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=818721\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You know the formulas <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=F=m%2Aa ALIGN=MIDDLE  ALT=\"F=m%2Aa\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d=%281%2F2%29at%5E2 ALIGN=MIDDLE  ALT=\"d=%281%2F2%29at%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > for distance traveled accelerating from rest.<BR>\n" );
document.write( "You do not need to memorize formulas, you just need to understand them and think with your own head.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=F=m%2Aa ALIGN=MIDDLE  ALT=\"F=m%2Aa\"   DISABLED_style= \"max-width:90%; height:auto;\" > <--> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=F%2Fa=m ALIGN=MIDDLE  ALT=\"F%2Fa=m\"   DISABLED_style= \"max-width:90%; height:auto;\" > is intuitive.<BR>\n" );
document.write( "If you need a lot more force to get the same acceleration for a car than for a baby carriage, it must be that the car is a lot heavier.<BR>\n" );
document.write( "If you need 100 times the force, it must be 100 times heavier.<BR>\n" );
document.write( "If the acceleration you achieve with the same force is a lot less for the car it's because its heavier.<BR>\n" );
document.write( "Acceleration is the change in velocity per second (we can say velocity is  speed, if we all go in the same direction).<BR>\n" );
document.write( "We divide distance by time once to get speed, then divide again to get acceleration.<BR>\n" );
document.write( "If it is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3 ALIGN=MIDDLE  ALT=\"3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=m%2Fs%5E2 ALIGN=MIDDLE  ALT=\"m%2Fs%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > , starting from rest, the speed will be<BR>\n" );
document.write( "3 m/s after 1 second<BR>\n" );
document.write( "3 m/s + 3 m/s = 6 m/s after another second (2 seconds from the start)<BR>\n" );
document.write( "9 m/s after 3 seconds<BR>\n" );
document.write( "12 m/s after 4 seconds<BR>\n" );
document.write( "15 m/s after 5 seconds<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=drawing%28200%2C600%2C-1%2C6%2C-3%2C18%2Cred%28arrow%285%2C15%2C6%2C18%29%29%2C%0D%0Agrid%280%29%2Cred%28arrow%280%2C0%2C10%2C30%29%29%2Crectangle%280%2C0%2C5%2C15%29%2C%0D%0Alocate%282%2C-0.5%2Cseconds%29%2Clocate%280.3%2C18%2C%22m%2Fs%22%29%2C%0D%0Alocate%284%2C17%2Cred%28speed%29%29%0D%0A%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" > For a constant 15 m/s speed, the graph would look like this <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=drawing+%28200%2C600%2C-1%2C6%2C-3%2C18%2C%0D%0Agrid%280%29%2Crectangle%280%2C0%2C5%2C15%29%2Cred%28arrow%280%2C15%2C6%2C15%29%29%2C%0D%0Alocate%282%2C-0.5%2Cseconds%29%2Clocate%280.3%2C18%2C%22m%2Fs%22%29%2C%0D%0Alocate%284.5%2C16%2Cred%28speed%29%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" > ,<BR>\n" );
document.write( "and the distance traveled in 5 seconds would be the constant 15 m/s speed times the 5 second travel time.<BR>\n" );
document.write( "That is the area of the rectangle between 0 and 5 seconds under the speed graph:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%2215+m+%2F+s%22%29%28%22+5+Seconds%22%29=75m ALIGN=MIDDLE  ALT=\"%28%2215+m+%2F+s%22%29%28%22+5+Seconds%22%29=75m\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "For a variable speed, the distance traveled is also the area under the speed curve.<BR>\n" );
document.write( "For the problem that area is a triangle, half the rectangle, 37.5 m.<BR>\n" );
document.write( "No formulas needed, but we can deduce them if we need them.<BR>\n" );
document.write( "Accelerating from rest the \"velocity\" <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v ALIGN=MIDDLE  ALT=\"v\"   DISABLED_style= \"max-width:90%; height:auto;\" > is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v=a%2At ALIGN=MIDDLE  ALT=\"v=a%2At\"   DISABLED_style= \"max-width:90%; height:auto;\" > ;<BR>\n" );
document.write( "the area of the rectangle would be time times that velocity <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=at%5E2 ALIGN=MIDDLE  ALT=\"at%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" >,<BR>\n" );
document.write( "and the distance traveled is half of that <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d=%281%2F2%29at%5E2 ALIGN=MIDDLE  ALT=\"d=%281%2F2%29at%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > . </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );