Suppose that two stars in a binary star system are separated by a distance of 80 million kilometers and are located at a distance of 150 light-years from earth.
a) what is the angular separation of the two stars in degrees?
b) what is the angular separation in arceseconds?

Select the correct text in the passage. the moving continents affect all subsystems on earth. which sentence identifies a potentially negative consequence of shifting continents? the supercontinent pangaea began to break up about 175 million years ago. [during this process, more coastline was exposed as the landmasses separated]. [the rearrangement and displacement of these huge landmasses resulted in the diversity of plants and animals we see on earth today]. [the movement of the plates sometimes leads to earthquakes and tsunamis]. however, over the long course of earth's history, their effects are usually minimal. in oceans, the plate movements usually lead to seafloor spreading. [seafloor spreading often results in the formation of underwater ranges of mountains].

What is a small water source like a stream or brook?

Mexico city is an example of how humans alter their environment because it was a. one of the world’s largest cities b. built on drained and filled lake beds c. built after conquest by the spanish d. once the capital of the aztec empire