need help with this problem

Question

What is the acceleration for a system compromised of two objects attached to one another: one with mass m1=45kg and the other with mass m2=55kg? The force that s acting on this system is equal to 60N and is directed toward the right

Answer 1

Treat the system as both of the objects: a = 60 N/(45kg+55kg)

The tension that holds the objects together is an internal force in this system, so it cannot affect the overall acceleration.