Name: duncan b smith
Date: 1993 - 1999
Why do planets closer to the sun travel faster than the outer
The speed with which planets etc. move around the Sun is proportional
to the force of Sun at the planet's position.
The force falls off with distance as inverse square so the planets closer to the
Sun experience a larger force and hence move faster.
This is a rough description. A more rigorous approach will involve mathematical
constructs like the gravitational potential.