How Can Precision and Setup Influence Metal Rod Mass Measurement Accuracy?

[DopplerFX]

Homework Statement

I am trying to determine the limitations to my experiment and thus how to improve them.
The experiment's objective is to determine the mass of a metal rod.
The rod is balanced every time another 1kg is added onto the end of the rod.
This means that the rod cannot be touching the clamp. (it has to be 'hovering' in between the jaws of the clamp)
A ruler with a precision of (+-1mm) was used
Ultimately, as the mass on the end increases, the distance (x) will decrease.
A graph was then plotted of (m), mass on the end of the rod against (1/x), 1/the distance between the pivot and the hook.
The setup is detailed below:

https://mail-attachment.googleusercontent.com/attachment/?ui=2&ik=401e948dbb&view=att&th=13646f85bd21f764&attid=0.1&disp=inline&safe=1&zw&saduie=AG9B_P_D6Q6VrNf2Vr2Br8SOfSkq&sadet=1332630638740&sads=Kdc3CmFjAgFH5owsYfUQG4Vliik

Homework Equations

Moment = Force x distance perpendicular to the line of action of the force
The linear cartesian equation: (y = mx + c) is equivalent to (m = MP(1/x) - M)
where m is the mass hanging on the end of the metal rod, M is the mass of the rod, P is a constant and x is the length from the pivot to the hook (where the mass is hanging).

Any ideas of the limitations and thus the improvements that could be made to this experiment? Thanks in advance.

 

[PeterO]

Homework Statement

I am trying to determine the limitations to my experiment and thus how to improve them.
The experiment's objective is to determine the mass of a metal rod.
The rod is balanced every time another 1kg is added onto the end of the rod.
This means that the rod cannot be touching the clamp. (it has to be 'hovering' in between the jaws of the clamp)
A ruler with a precision of (+-1mm) was used
Ultimately, as the mass on the end increases, the distance (x) will decrease.
A graph was then plotted of (m), mass on the end of the rod against (1/x), 1/the distance between the pivot and the hook.
The setup is detailed below:

https://mail-attachment.googleusercontent.com/attachment/?ui=2&ik=401e948dbb&view=att&th=13646f85bd21f764&attid=0.1&disp=inline&safe=1&zw&saduie=AG9B_P_D6Q6VrNf2Vr2Br8SOfSkq&sadet=1332630638740&sads=Kdc3CmFjAgFH5owsYfUQG4Vliik

Homework Equations

Moment = Force x distance perpendicular to the line of action of the force
The linear cartesian equation: (y = mx + c) is equivalent to (m = MP(1/x) - M)
where m is the mass hanging on the end of the metal rod, M is the mass of the rod, P is a constant and x is the length from the pivot to the hook (where the mass is hanging).

Any ideas of the limitations and thus the improvements that could be made to this experiment? Thanks in advance.

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