What is a variable speed drive? A variable speed drive is a piece of equipment that regulates the speed and rotational force, or torque output, of an electric motor. The background and technology. There are millions of motors in use in industry and offices around the world.
The specific gravity for Obsidian is 2.35, it's refractive index is 1.48-1.51, and it's double refraction is None. History Obsidian is named after a Roman, Obsius.
Casey Handmer, Physicist and levitation engineer at Hyperloop, pilot, adventurer, musician. Obsidian is a glassy volcanic rock. It is most likely to be found in areas of past or present volcanism, where effused rock rapidly cooled by contact with water, snow, or ice.