Friction/ Equlibrium

1. Jan 29, 2006

wayneo

Hi, please anyone help me to answer this question

A mass m,is attached to 2 equal peices of string each of length, whose ends are attached to rings around a rod. If the static coefficient of friction between the rings and the rod is u, find the largest distance d between the rings such that the mass is at equilibrium.

2. Jan 29, 2006

Hootenanny

Staff Emeritus
Can you show some of your working / thoughts?

3. Jan 29, 2006

wayneo

Ive got the answer as d= 2uL/square root of (1 + u squared) but Im a bit stuck with the working out

4. Jan 29, 2006

Hootenanny

Staff Emeritus
Have you drawn a diagram showing all the forces acting?

5. Jan 29, 2006

wayneo

no but there arent any forces given as it is in equilibrium

6. Jan 29, 2006

wayneo

nemore ideas?

7. Jan 29, 2006

wayneo

any1 ??????

8. Jan 29, 2006

wayneo

hard huh ?

9. Jan 29, 2006

Hootenanny

Staff Emeritus
There are forces but they are all balanced. Try calculating the tension in the strings, then resolving the tension horizontally parallel to the rod.

Last edited: Jan 29, 2006
10. Jan 29, 2006

sporkstorms

I think what you're trying to say is that there is no net force. There are, most certainly, forces acting in the system.

Listen to Hootenanny, s/he speaks words of wisdom.

Your goal is to find out where those rings will be when the net force is zero. In order to do so, you really need to make a diagram.

11. Jan 29, 2006

Hootenanny

Staff Emeritus
Thank-you sporkstorms