# M1 - Ring, string, tension Q.Watch

#1
Two small rings, A and B, each of mass 2m are threaded on a rough horizontal pole. The coefficient of frictrion between each ring and the pole is u. The rings are attached to the ends of a light inextensible string. A smoth ring C, of mass 3m, is threaded on the string and hangs in equlibirum below the pole. The rings A and B are in limiting equilibrium on the pole, with angle BAC = angle ABC = x, where x = tan 3/4, as shown in the diagram.

a) Show that the tension in the string is 5mg/2.
b) Find the value of u.

My approach to this seemed to be completely wrong. I don't think it's worth posting.

Any help greatly appreciated
0
8 years ago
#2
The way to start is to look at each point individually and draw all the forces.
As the system is in equilibrium so much the points be
You should be able to find expressions for unknown forces from comparing the points
0
#3
Okay I seriously have no idea where to start.
Any help greatly appreciated.
0
X

new posts
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• University of the West of England, Bristol
Wed, 23 Jan '19
• University of East London
Wed, 23 Jan '19
• University of Gloucestershire
School of Education Open Day Postgraduate
Wed, 23 Jan '19

### Poll

Join the discussion

Remain (1623)
79.13%
Leave (428)
20.87%