$A$ particle is moving in an elliptical orbit as shown in the figure. If $\vec{p}$, $\vec{L}$, and $\vec{r}$ denote the linear momentum, angular momentum, and position vector of the particle (from focus $O$) respectively at point $A$, then the direction of $\vec{\alpha} = \vec{p} \times \vec{L}$ is along

Consider a star of mass $m_2 \ kg$ revolving in a circular orbit around another star of mass $m_1 \ kg$ with $m_1 \gg m_2$. The heavier star slowly acquires mass from the lighter star at a constant rate of $\gamma \ kg/s$. In this transfer process,there is no other loss of mass. If the separation between the centers of the stars is $r$,then its relative rate of change $\frac{1}{r} \frac{dr}{dt} \ (\text{in } s^{-1})$ is given by:

Define the periodic time (orbital period) of a satellite.

Orbital velocity of an artificial satellite does not depend upon

$A$ planet of mass $M$ has a satellite of mass $m$,revolving around the planet in a circular orbit of radius $r$ and time period $T$. The mass $(M)$ of the planet is

The orbital velocity of a planet revolving close to the Earth's surface is: