Newton's laws of motion — practice question

A light inextensible string carries a particle $A$ of mass $0.26\text{ kg}$ at one end and a particle $B$ of mass $0.54\text{ kg}$ at the other. Particle $A$ is kept at rest on a rough plane inclined at angle $\alpha$ to the horizontal, where $\sin\alpha = \frac{5}{13}$. The string is taut and runs parallel to a line of greatest slope on the plane. It passes over a small smooth pulley at the top of the plane. Particle $B$ hangs motionless vertically below the pulley. The coefficient of friction between $A$ and the plane is $0.2$. Particle $A$ is released, and the particles begin to move.