Understanding Friction: A Systematic Approach to Solving Problems

[ritwik06]

Homework Statement

I have been facing constant problems in solving questions about friction. I wish to formulate a general method of solving such questions.
http://img71.imageshack.us/img71/3535/frictionzf3.jpg
Here u1, u2 and u3 are friction coefficients. (Assume kinetic coefficient to be same as limiting static coefficient )
I wish to find the acceleration in each block in a systematic manner when a force F is applied on block
1) A
2) B
3) C

Help me discern a solution in a systematic manner in order that I may remember it for a long time.

 

[CompuChip]

What answer would you like us to give? :)

 

[ritwik06]

What answer would you like us to give? :)

1)Proceeding for the first part. A force F Newton is applied on block A. My aim is to calculate the acceleration of all the 3 blocks. How shall I proceed?
Someone please help me. I am not asking for solution but please will you guide me through it??

 

[ritwik06]

Please help me guys

 

[CompuChip]

Sorry, I missed your previous post.

OK so let's start with the first case then. First try to describe in words (well, you can use formula's, but not entire calculations) what will happen when the force is applied? Well, that depends on the magnitude of the force. Can you say what happens in the two possible scenario's, and what the transition between them is? Do you know of any formulas that will give the frictional force of the top block on the one below it, in the two different cases?