The discussion revolves around the concept of work in physics, particularly focusing on scenarios where the work done by forces, such as normal force and static friction, is zero. Participants explore the definitions and conditions under which work is calculated, especially in relation to angles between force and displacement vectors.
The discussion is active, with participants providing insights into the conditions under which work is zero. Some have offered explanations regarding the normal force and its relationship to displacement, while others are probing deeper into the nature of static friction and its lack of work contribution.
There is an ongoing exploration of definitions and assumptions related to static and kinetic friction, as well as the geometric relationships involved in calculating work. Participants are encouraged to clarify their understanding without reaching a definitive conclusion.
parwana said:W= Fx
Thats work. But there also can be an angle between them
You have already I think determined from the help of the responders that the work is zero when the displacement is 90 degrees to the force. Generally the normal force is 90 degrees to the displacemnt vector, so it does no work. Like when you push a block along a level table, the normal force between the block and table acts straight up on the block, and the block moves perpendicularly to it (to the right). so the normal force does no work (W=Ndcos90 = 0). But you still have another question to answer. Why does the static friction force generally not do any work? It's for a different reason.parwana said:can anyone help and explain in detail
What does static mean?parwana said:^ that's what I don't get, why doesn't static friction not do any work. Usually friction is in the opposite direction as the movement right. Now how can that make it not work?
When an object is moving, it is subject to kinetic friction, not static friction. Kinetic friction does lots of work, since the kinetic friction force is in the same direction of the displacement.. But what can you say about static friction force and displacemnt?parwana said:^ that's what I don't get, why doesn't static friction not do any work. Usually friction is in the opposite direction as the movement right. Now how can that make it not work?