Acceleration/Tension between two masses

1. The problem statement, all variables and given/known data

I am currently taking a Summer physics course, and today we were given a Force/Friction problem that even after the professor explained, I could not fully understand.

Mass of Objects: m1=5.0kg m2=2.0kg

Given Friction Valules: Mk1 (Between Block and Surface) = 0.20 Mk
Mk2 (Between Blocks) = 0.15

I am supposed to find acceleration, as well as the tension between the two masses.

2. Relevant equations

Equations that he used to solve the problem:


Force-Kinetic Friction-Tension = mass*acceleration

3. The attempt at a solution

I was able to draw a free body diagram of the system, however, I only included 2 values for normal force and Kinetic Friction, where in his complete Free Body Diagram, there were 3 values for both. I really got lost when he solved the problem using a system of equations towards the end.

The acceleration ended up being 80/7 m/s2, or about 11.4 m/s2, and tension ended up being around 26 N.

I have been studying this topic, but I don’t really understand the fundamentals of the whole process, and memorizing formulas hasn’t helped whatsoever. Any guidance would be greatly appreciated!

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