When a rock tied to a string is whirled in a horizontal circle, doubling the speed .

If we represent the solar system on a scale that allows us to walk from the sun to pluto in a few minutes, then a) the planets are microscopic and the stars are millions of miles away. b) the planets are the size of basketballs and the nearest stars are a few miles away. c) the planets are marble size or smaller and the nearest stars are thousands of miles away.

The biome that includes evergreen trees is the forest biome.

The dashed segment of the plotted experiment in the graph in the lesson is called an