Explain Cartesian components of angular momentum of a particle.
By definition of angular momentum
$\vec{l}=\vec{r} \times \vec{p}$
$\hat{i}\hat{j}\hat{k}$
$x\;y\;z$
$\mathrm{P}_{x}\mathrm{P}_{y}\mathrm{P}_{z}$
$=\hat{i}[y \mathrm{P} z-z \mathrm{P} y]+\hat{j}[z \mathrm{P} x-x \mathrm{P} z]+\hat{k}[x \mathrm{P} y-y \mathrm{P} x] \ldots \ldots . .(1)$
$\therefore \vec{l}=l_{x} \hat{i}+l_{y} \hat{j}+l_{z} \hat{k}$
Here $l_{x}, l_{y}$ and $l_{z}$ are the components of $\vec{l}$ along $\mathrm{X}, \mathrm{Y}$ and $Z$ axis respectively.
A spherical shell of $1 \,kg$ mass and radius $R$ is rolling with angular speed $\omega$ on horizontal plane (as shown in figure). The magnitude of angular momentum of the shell about the origin $O$ is $\frac{a}{3} R^{2} \omega$. The value of a will be ..............
A particle of mass $20\,g$ is released with an initial velocity $5\,m/s$ along the curve from the point $A,$ as shown in the figure. The point $A$ is at height $h$ from point $B.$ The particle slides along the frictionless surface. When the particle reaches point $B,$ its angular momentum about $O$ will be ......... $kg - m^2/s$. [Take $g = 10\,m/s^2$ ]
The potential energy of a particle of mass $m$ at a distance $r$ from a fixed point $O$ is given by $\mathrm{V}(\mathrm{r})=\mathrm{kr}^2 / 2$, where $\mathrm{k}$ is a positive constant of appropriate dimensions. This particle is moving in a circular orbit of radius $\mathrm{R}$ about the point $\mathrm{O}$. If $\mathrm{v}$ is the speed of the particle and $\mathrm{L}$ is the magnitude of its angular momentum about $\mathrm{O}$, which of the following statements is (are) true?
$(A)$ $v=\sqrt{\frac{k}{2 m}} R$
$(B)$ $v=\sqrt{\frac{k}{m}} R$
$(C)$ $\mathrm{L}=\sqrt{\mathrm{mk}} \mathrm{R}^2$
$(D)$ $\mathrm{L}=\sqrt{\frac{\mathrm{mk}}{2}} \mathrm{R}^2$
A particle of mass $m$ is moving with constant velocity $v$ parallel to the $x$-axis as shown in the figure. Its angular momentum about origin $O$ is ..........
In an orbital motion, the angular momentum vector is