1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution Working from the reference frame of block , a pseudo force Ma0 towards right need to be applied on the cylinder . Forces acting on the cylinder are pseudo force , weight Mg and normal force from the block (if any) . Since the cylinder does not have horizontal acceleration , N sin30° = Ma0 . I am not able to proceed from here . Any help would be appreciated .