In this question use $g=9.8$ m s${}^{-2}$.

Two particles $A$, of mass 2 kg, and $B$, of mass 3 kg, are connected by a light inextensible string. The string passes over a smooth pulley fixed at the top of a rough plane inclined at $40°$ to the horizontal.

$A$ lies on the plane with the string parallel to a line of greatest slope, and $B$ hangs freely with the string taut.

The system is released from rest and $A$ accelerates up the plane at 2 m s${}^{-2}$.