Question

Angular momentum Question

Answer 1

The derivative with respect to time, of a constant factor should be zero.

Answer 2

hi @UnkleRhaukus thank you for your response. Except do you mind explaining how I could prove what has been asked?

Answer 3

\[\vec{F}=-\frac{c}{|\vec{r}|^3}\vec{r}\]\[\vec{L}=\vec{r}\times\vec{p}=\vec{r}\times m\vec{v}\]\[\frac{d\vec{L}}{dt}=\frac{d\vec{r}}{dt}\times m\vec{v}+\vec{r}\times m\frac{d\vec{v}}{dt}=\underbrace{\vec{v}\times m\vec{v}}_{=0}+\vec{r}\times m\vec{a}=\vec{r}\times\vec{F}=-\vec{r}\times\frac{c}{|\vec{r}|^3}\vec{r}=0\]