# tension and friction

I had an exercise like the image, where block A is pulled by a force F, there is that rope(tension) attached to the block B and the wall, and there is friction between A and B, and A and the ground, and the coefficent of friction is the same in both cases. The question asks us what is the intensity of the force required to start moving the blocks.

My doubt is: we know tension is only applied in block B, but are we supposed to apply it on block A as well? Because it is the only way I get a solution equal to the solutions of the book.

• The rope is attached to $B$. Therefore, there is no force from the rope on $A$. There must be another mistake in your work. – Jerry Schirmer Apr 22 '16 at 22:21
• Have you drawn a free body diagram on A and B separately, or do you feel that you have advanced beyond the point where you need to use free body diagrams? – Chet Miller Apr 23 '16 at 12:07