What is the main difference between a refracting telescope and a reflecting telescope? a refracting telescope uses a concave lens to collect light; a refracting telescope uses a concave mirror to collect light. a refracting telescope uses a convex lens to collect light; a refracting telescope uses a convex mirror to collect light. a refracting telescope uses a convex lens to collect light; a refracting telescope uses a concave mirror to collect light.

Imagine you had to physically add electrons, one at a time, to a previously neutral conductor. you add one electron very easily, but the second electron requires more work. in your initial post to the discussion, explain why this is. also, what happens to the work needed to add the third, fourth, fifth, and subsequent electrons

Arotating space station is said to create “artificial gravity”—a loosely-defined term used for an acceleration that would be crudely similar to gravity. the outer wall of the rotating space station would become a floor for the astronauts, and centripetal acceleration supplied by the floor would allow astronauts to exercise and maintain muscle and bone strength more naturally than in non-rotating space environments. if the space station is 200 m in diameter, what angular velocity would produce an “artificial gravity” of 9.80 m/s^{2} 2 at the rim?

The softest and hardest minerals are: softest hardest