experiment
I used a similar machine. Mine had two pulleys. I would not think pulley mass would have an effect because I used the same pulley and set up for each mass I dropped. I first balanced two masses. then I added 5 grams of weight to one side and measured the time it took to fall 1...
I used atwoods machine to test the affect of mass on the speed of falling bodies. My research said objects fall at the same rate no matter their weight. When I tested this on Atwoods machine heavier masses fell faster. Can someone tell me why?