How Do You Calculate the Tension in a Rope Between Two Blocks?

[pleasehelpme1]

1. There is a 45 kg block that is connected to a 30 kg block by a mass-less rope. The surface is frictionless. A force of F=200 N pulls the blocks to the right and in the positive direction. What is the magnitude of the tension T in the rope that connects the two blocks?


2. I am not sure what equation to use on this particular problem.



3. I made a free-body diagram for the forces but I don't understand how to find the tension of the rope.

Thank you.

 

[VACA]

What does your diagram look like?