# Friction question

1. Mar 19, 2009

### tnutty

Imagine a pulley system, where a puck is connected by a massless string to a massless pulley that joins a mass m thats hanging at the end of the table.

Would the force of friction change as you increase mass m , the object thats hanging? why so?

This is not a HW question.

2. Mar 20, 2009

### sonofahb

no, because the string and pulley are massless?

3. Mar 20, 2009

### Staff: Mentor

Pretty weird general interest question. Sure sounds like homework/coursework.

What is the research/work context of your question?

4. Mar 28, 2009

### Archosaur

5. Mar 28, 2009

### Staff: Mentor

I assume you mean the force of friction on the puck. How would you calculate that force?

6. Mar 28, 2009

### Cantab Morgan

tnutty, I think what you're asking is, if I could somehow "dial down" gravity (with a possibly elaborate system of pulleys and counterweights), would friction decrease?

Well, you tell me. In the case of static friction, which is what you appear to have described, does the fricative force depend on the Normal force? Or is is just whatever value is needed to oppose motion?