Free body diagrams and Newton's Law

[Kenny Wallace]

Homework Statement

2 masses, m1 and m2 are connected by a cord and placed on a frictionless table as
shown in the diagram below. m1 slides on the frictionless table while m2 is hanging from a light frictionless pulley.
What would be the mass of the hanging mass m2 if we know that the tension in the cord is T and the mass of the sliding mass is m1

The Attempt at a Solution

I drew a free body diagram for the system as a whole then I got that resultant force on the whole system is F=mg since it is only the weight of the two blocks. I don't really know how to go on from there.

 

[haruspex]

It's generally better to consider a separate FBD for each body.