The Eotvos Experiment: Discussion and Analysis

[thecoop]

the eotvos experiment consists of two objects of different composition connected by a rod of length l and suspended horizontally by a fine wire . if the gravitational acceleration of the two masses is different then there will be a torque , I saw this equation in the most of texts without derivation , what do you think guys ?

 

[Vanadium 50]

I see equations without derivations in textbooks too sometimes.

 

[Nugatory]

the eotvos experiment consists of two objects of different composition connected by a rod of length l and suspended horizontally by a fine wire . if the gravitational acceleration of the two masses is different then there will be a torque , I saw this equation in the most of texts without derivation , what do you think guys ?

You are asking why it follows that there will be a torque? It's a pretty easy derivation, you can do it yourself just by calculating the forces on the end of the rod that would be produced if gravitational mass differed from inertial mass under various conditions. Or check out the wikipedia article.

Some experiments are conceptually very simple, yet because of the subtlety of the effect that's being studied, extraordinarily difficult to do well. Textbooks generally are trying to present the concepts and theory, so tend to present these experiments in a sort of idealized form that conceals just how had it can be to actually do the experiment well.