About Planets

Spacemen Fred's spaceship (which has negligible mass) is in an elliptical orbit about planet Bob. The minimum distance between the spaceship and the planet is R, the maximum distance between the spaceship and the planet is 2R. At the point of maximum distance, spaceman fred is traveling at speed v_(0) . he then fires his thrusters so that he enters a circular orbit of radius 2R. what is his new speed?

What are inner planets and outer planets ? Name them .

Identify the incorrect statement about a planet revolving around Sun

Which of the following statements are correct about a planet rotating around the sun in an elleptical orbit

A : Angular momentum of a satellite about a planet is constant . R :Gravitational force is a central force so its torque about the sun is zero .