The pulley is not, in fact, frictionless and massless. At the beginning of the lab you found

the mass difference needed to start movement of the system. How can this data be used to
approximate the effect of friction?

1 answer

The mass difference can be used to approximate the effect of friction by calculating the amount of force needed to move the system. This can be done by dividing the mass difference by the acceleration due to gravity (9.8 m/s2). The resulting force can then be used to approximate the amount of friction in the system.