Question

A satellite revolves around a planet in an elliptical orbit. Its maximum and minimum distances from the planet are 1.5 × 10⁷ m and 0.5 × 10⁷ m respectively. If the speed of the satellite at the farthest point be 5 × 10³ m/s, calculate the speed at the nearest point.

Answer 1

In case of elliptical orbit, the speed of satellite varies constantly as shown in figure. Thus according to the law of conservation of angular momentum, the satellite must move faster at a point of closest approach (Perigee) than at a farthest point (Appogee).

Substituting the given values, we get