Hi, this is probably something basic I am missing but I can't get my head around it.
In the question you are told that A and B are particles of mass 3m and m respectively, each attached to a light inextensionable string of length 3h. The string passes over a smooth pulley attached to a rough table. The coefficient of friction between the table and A is

.
The system is released from rest and begins to move...
1. Show that until B hits the floor, the acceleration of A is

, this I was able to do.
2. Find the speed of A immediatly before B hits the floor, managed to do this as well, got it to be
3. After B hits the floor, A continues to move, coming to rest before reaching the pulley. Deduce the range of values of

for the motion above to be possible.
It is the last bit I can't get my head round, any ideas?
Thanks in advance
Craig