Possible sources of error/uncertainty in bifilar pendulum?

[ah4p]

in my AH physics investigation - measuring acceleration due to gravity, I used the bifilar suspension pendulum btw a light gate was used

for the errors/problems section so far I have problems in making the rod level and keeping the two strings parallel, also all the random, calibration and scale reading uncertainties have been mentioned

I can't think of anything else??

trying to do my advanced higher bio investigation and woodwork project at the same time so need to get this done

thanks very much in advance :D

 

[OldEngr63]

You probably made some small angle assumptions. Those are strictly valid only for very small angles, so for angles large enough to measure easily, that is another error source.