A person is sitting on a swing/seat/platform and pulling himself up with a rope. Don't worry about the swing part. One end of the rope is attached to 2 other metal wires connected to the seat. The other end of the rope is attached to a spring scale and is being pulled by the person. The rope goes above and passes through a pulley. Like in this diagram. http://imageshack.us/a/img845/3343/phydia2.png [Broken] the swing weighs 160n, the person weighs 320n and the scale reads 250n. Is the swing/seat/platform going up or down? What is the force exerted by the person on the seat. What is the acceleration of the system. Since scale reads 250n that should be tension in the rope. he must be exerting 250n. Thus 320+160 >250 thus he is going down. The hard part of this question is that when the person pulls the rope/scale does the rope or scale pull him back up? Because if it does then technically he'd be going up. In this question can i replace his pull with a 250n block of mass? If he is going up, how is it possible for someone to exert 250n and move 480n up without mechanical advantage.