If the distance between the earth and the sun were half of its present value, the number of days in a year would have been

The earth rotates about the sun (see Fig. 12.54) in an elliptical orbit. At which point is velocity maximum?

In a satellite if the time period is $T$, then $K\mathit{,}\mathit{ }E$, is proportional to

An artificial satellite revolves around the earth in circular orbit with a speed $v$. If $m$ is the mass of the satellite, its total energy is