Question

Figure shows the variations of energy $E$ with the orbit radius $r$ of a satellite in circular motion. Choose the correct statement.

• A. $A$ shows the kinetic energy, $B$ shows the total energy and $C$ the potential energy of the satellite
• B. $A$ and $B$ are kinetic energy and potential energy respectively and $C$ the total energy of the satellite
• C. $A$ and $B$ are the potential energy and kinetic energy respectively and $C$ the total energy of the satellite
• D. $C$ and $A$ are the kinetic and potential energies and $B$ the total energy of the satellite

Answer 1

Answer: (B)

Kinetic energy of the satellite, $K = \frac{GMm}{2r}$
Potential energy of the satellite, $U = -\frac{GMm}{r}$
Total energy of the satellite, $E = -\frac{GMm}{2r}$
In figure,

Variation of $K$ with $r$ is shown by curve $A$.
Variation of $U$ with $r$ is shown by curve $B$.
Variation of $E$ with $r$ is shown by curve $C$.