
#1
Mar612, 08:41 PM

P: 867

When deriving the workpotential energy theorem, my book states that dV (derivative of the potential energy) is equal to the negative of Fdr without a corresponding explanation. What is the justification behind the negative sign?




#2
Mar612, 09:06 PM

P: 51

As such,there is no explanation,its about definition.
The important thing is,for conservative forces,you can define a potential.Even if you had define dV=Fdr,you would have a consistent theory.The fact that dV=Fdr,and not Fdr,is not logic,its convention. In essence,it means that,when positive work is done by the field forces on body,its potential energy decreases,and kinetic energy increases. 


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