A person of mass M is standing in a box of mass m and pulling the same box with acceleration a by applying a force F as shown in the diagram. Let N is the force on man by box.
System, FBD & Newton’s law
Rope (massless): 0. a = T – F
Person (M) : Ma = (T + N) – Mg
Box (m): ma = T – (N + mg)
Simplifying these equations we get,