The problem involves a pulley system with a mechanical advantage of 3, where a box weighing 420N is lifted 6m using a force of 140N applied over a distance of 18m. The discussion centers around calculating the work done in this scenario, considering the definitions and implications of work in a mechanical context.
Some participants have provided insights into the definitions of work and the forces at play in the pulley system. There is an ongoing exploration of how to correctly calculate work based on the forces involved and their respective distances. Multiple interpretations of the problem are being discussed, particularly regarding the distinction between the force applied to the rope and the force acting on the box.
Participants note the importance of specifying which force is being considered when discussing work, as well as the implications of mechanical advantage in the context of the problem. There is also a mention of ideal conditions, such as the absence of friction, which may affect the calculations.
Welcome to the PF.V1NW3N said:
No. The force of 140 N is exerted over a distance of 18 m. (The box moves 6 m, but the force on the box equals its weight, not 140 N.)V1NW3N said:
When asking work, it should be specified "work of what force on what body".V1NW3N said:
V1NW3N said:
Well, the force on the box is equal its weight and the tension from the pulley system, in opposite direction. If it does not accelerate, the net force on the box is zero.Doc Al said:
I meant the force that the pulley system exerts on the box, not the net force on the box.ehild said:
That's the force doing the work against gravity on the box, which is what we care about here.