Moment of force - Aetherwisp

The moment of force $\mathbf{N}$ , or torque, of an object at position $\mathbf{r}$ about a point $O$ subject to a force $\mathbf{F}$ is the cross product

\mathbf{N}=\mathbf{r}\times \mathbf{F}

where $\mathbf{r}$ is the vector connecting $O$ with the object. When referred to as "torque", it typically uses the letter $\tau$ instead. A moment of force generates an angular momentum $\mathbf{L}$ in the same fashion as a force generates a linear momentum. In fact, using Newton's second law:

\mathbf{N}=\mathbf{r}\times \frac{d\mathbf{p}}{dt}=\frac{d}{dt}(\mathbf{r}\times \mathbf{p})=\frac{d\mathbf{L}}{dt}=\dot{\mathbf{L}}