A long block A is at rest on a smooth horizontal surface. A small block B, whose mass is half of A, is placed on A at one end and projected along A with some velocity u. The coefficient of friction between the blocks is `mu`:

Options

A. The blocks will reach the final common velocity `u/3`
B. the work done against friction is two-thirds of the initial kinetic energy of B
C. before the block reach a common velocity the acceleration of A relative to B is `2/3 mu g.`
D. Before the blocks reach a common velocity the acceleration of A relative to B is `3/2 mu g.`

Answer

A, B, D