Question

find the acceleration of the blocks 2kg,1kg initial velocity is 0.5.force is 20N

Answer 1

As the block B, together with block A is laying on rough surface with u=0.5(u is not the initial velocity it is mu) it will be able to accelerate if the applied force is greater than u(mA+mB)g=0.5(10)(10)=50N.

Hence the force applied is only 25N .hence there will be no acceleration and frictional force between A & B will not arise .

force between A and B is zero