Based on your observations of the orbits of the Moon, Earth, and Venus, how does the radius of an orbit relate to the average speed of the orbiting body?

This is the speed we travel 24 hours a day, 365.25 days a year. The orbital velocity is 2πR/T where R is the average radius of the orbit and T is the length of the year. The orbital velocity of a planet relative to that of Earth's is then the relative radius divided by the relative length of the year.

Geologists use  seismic waves to  locate an earthquake's epicenter.. 

Answer accretion;