# Homework Help: Help with connected particles

1. Oct 31, 2004

### Ihsahn

OK, this problem is causing serious... well, problems!

(NB, I'm not sure whether this classes as 'College' or 'K-12', I've posted in both, so could someone with the power to delete the 'K-12' one? Thanks)

A ring of mass 3m can slide on a fixed smooth vertical wire. The ring is attached to a light inextensible string which passes over a small smooth pulley fixed at distance d from the wire. The other end of the string is fixed to a particle of mass 5m which hangs freely. Given that the system is in equilibrium, find:

a) the length of the string between the ring and the pulley (this one I could do, its 5d/4)

b) the magnitude of the reaction between the ring and the wire

c) the magnitude and direction of the reaction on the pulley

(I have a feeling those two could be very easy, and I'm just not seeing something)

The ring is then lifted and released from rest on the same horizontal level as the pulley

d) Use the principle of conservation of energy to find how far the ring will fall before it first comes momentarily to rest.

If this is actually simple and I'm just not spotting it, I apologise, but I've been staring at it for ages! Any help would be much appreciated.

Thanks,

Rob