A comet is in an elliptical orbit about the Sun, as diagrammed below:

The mass of the comet is very small compared to the mass of the Sun.

In the diagram above, how does the net torque on the comet due to the Sun's gravitational force compare at the two marked points?

A satellite is in an elliptical orbit about the Earth. If the satellite needs to enter a circular orbit at the apogee of the ellipse, in what direction will it need to accelerate?

If is the escape velocity from the surface of a planet of mass and radius . What is the velocity necessary for an object launched from the surface of a planet of the same mass, but with a radius that is , to escape the gravitational pull of this smaller, denser planet?

A satellite of mass is in an elliptical orbit about the Earth. It's velocity at perigee is and its orbital radius at perigee is . If the radius at apogee is , what is its velocity at apogee?