Question

Two blocks of masses m and 2m are
placed on a smooth horizontal surface
as shown. In the first case only a force
F. is applied from the left. Later only a
force F, is applied from the right. If the
force acting at the interface of the two
blocks in the two cases is same, then
F:F, is
(Physics Olympiad 2016)​

Answer 1

1:2

the explanation is given in the above picture