We've been given a lab in physics class to verify that F=ma graphically. To do this we had a cart with weights on top be pulled by a string with weights on the other end over a pully pull the cart down, bringing weights off the cart to the end of the string to keep the mass constant, but changing the force. Doing this with 7 different weights produced 7 sets which we graphed with F on the x-axis, and a on the y-axis. The problem is the slope of the Fa graph which I would have thought to be m, is aparently half m. Anyone have any idea why? This one is beating me over the head :(. Thanks in advance.