Why Do Stars in the Disk of a Spiral Galaxy

question 11

Multiple Choice

Why do stars in the disk of a spiral galaxy orbit in roughly the same direction, in the same plane in space?

• A)The gas that formed the stars was shaped as a giant, rotating disk.
• B)Collisions between the stars caused their motions to organize into a general, spinning disk direction.
• C)After the stars formed, gravity pulled the stars down into a plane in space, all orbiting a supermassive black hole.
• D)It is pure coincidence; the stars just happen to be going in the same direction.

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Definitions:

Competitive Firm

A company that operates in a market with many other firms, selling similar or identical products or services, where no single firm can influence market prices.

Total Economic

A comprehensive assessment of all economic activities within a specific region, including total revenue, expenditures, and income.

Break-even Point

The point at which total costs and total revenues are equal, meaning that a business, project, or investment is neither making a loss nor a profit.

Normal Profit

The minimum profit necessary for a company to remain competitive in the market; it corresponds to the opportunity cost of capital.