Skip to main content

All Questions

-1 votes
1 answer
116 views

How does one prove that the conservative force $\vec{F}$ is equal to the negative gradient of the potential $V$?

I have a grasp of the gradient theorem, and I understand that if we let $\phi$ be a function such that $\vec{F}=\nabla \phi$, and $V(\vec{x})$ be the potential at $\vec{x}$, then $$-\int _C\vec{F}d\...
Sam's user avatar
  • 379
1 vote
1 answer
146 views

How to choose the sign of the differential?

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$. An object moves from a to b,...
能够可能's user avatar
0 votes
1 answer
268 views

Integral limits when calculating the work

If I integrate $$dW= \vec{ F} \cdot d\vec{\ell}$$ which are the limits? In $$\int\limits_{W_{inf}}^{W_{sup}}dW= \int\limits_{\vec{\ell}_{1}}^{\vec{\ell}_{2}} \vec{ F} \cdot d\vec{\ell}$$ it is ...
Alex Pacini's user avatar
2 votes
2 answers
2k views

Definition of torque for a continuous body

I am working on basic physics definitions. Given a particle at position $r$ (in some coorinate reference system) upon which acts a force $F$, the $torque$ $\tau$ is defined by \begin{equation} \tau:=r\...
marco trevi's user avatar