How to apply Newton's second law with a free body diagram

[Oblakastouf]

Homework Statement

Homework Equations

F = Ma

The Attempt at a Solution

... I wish I even knew where to start :\
I drew the freebody diagram, but I don't know how to use it.

 

[nike5]

I believe the net force acting on the tin of corned beef must be 2.3 Kg x 5.4 m / s2= 12.42 N. Set this equal to the other forces acting on the tin.

 

[Oblakastouf]

I don't even know how to do that :\ I kinda just need a similar problem solved so I can make a method out of how they did it... I need to figure out how to change free body diagrams into an equation. You miss one day of class and you get f-cked.