In Fig the co - efficient of friction between the walls of block of mass `m` and the plank of mass `M` is `mu` The same co- efficient of friction is there between the plank and the horizontal floor The force `F` is of `100 N` and the masses `m` and `M` are of `1 kg` and `3kg` respectively Find the value of `mu `.If the block does not slip along the wall of the plank

Answer

`mu=0.5 or mu=2`