Atwood Machine, weight of the string

[melvis]

1. In the experiment(using a Atwood machine), should the mass of the string be added to the total mass moved by the unbalanced force for better accuracy? Explain.

I think the answer is no because the weight of the string is very small and when doing the calculations to find acceleration, one would have to subtract the weight of the string just like we subtract the pulley friction force. Did I get it right? thanks for your time.

 

[PhanthomJay]

Generally speaking, yes, the weight of the string can be neglected because it is usually quite small in comparison to the masses, and won't change significant figure accuracies. This would not be the case if the string was a heavy rope and the masses being supported were small in comparison.