Is Static Friction Capable of Doing Work?

[russ_watters]

Try this, pixel01 - draw a picture of the system, then draw a circle around the part you want to analyze. For any of these scenarios, knowing how to properly define the system is the key. For the stacked-boxes example, you would draw your circle around the ground, the entire lower box, and part of the upper box - but not the person's finger. That way the only force you are looking at is the force between the boxes and the only motion is between the lower box and the ground.

 

[pixel01]

Right, the work can be negative and the spring example is meaningless.

Anyway, I am not convinced at the statement: static friction (or string, bolts or nuts...) can do work.

 

[miss photon]

i think we can say that static friction is capable of doing work in certain frames of reference.

 

[russ_watters]

Not sure how to help you - have you tried drawing a picture?

 

[arildno]

Right, the work can be negative and the spring example is meaningless.

Anyway, I am not convinced at the statement: static friction (or string, bolts or nuts...) can do work.

Why not?

You have some type of misconception here.