Atwood Machine 3 different mass

Tracker Experiment

Atwood Machine 3 different mass

The cart are 0.2, 0.3, 0.4 kg respectively.
The same mass are suspended from the pulley.
Why are the forces different?
What is the mass being suspended?

A: Tension is reduced when mass is accelerated. mass is 100 g.

Author: Leong Tze Kwang