Which of the Following Is Not a Way That Astronomers

question 31

Multiple Choice

Which of the following is not a way that astronomers can find how much dark matter there is in cluster of galaxies?

• A) measuring the speeds with which the galaxies are moving around, to estimate the mass of the cluster needed to keep them from moving away
• B) measuring how much slower galaxies in a rich cluster or supercluster are moving than the Hubble Law would predict
• C) observing x-rays from the hot gas in the cluster, and using the amount of x-ray radiation to estimate the mass of the cluster
• D) using gravitational lensing effects to make a map of how much mass a cluster of galaxies contains
• E) observe the radio waves coming from all dark matter; from the strength of the radio waves from each cluster, estimate the amount of dark matter needed to produce them

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Definitions:

Fixed Cost

A cost that does not change with the volume of sales.

Fixed Costs

Expenses that do not change in proportion to the activity of a business, such as rent, salaries, and loan payments.

Variable Costs

Costs that vary directly with the level of production or sales, such as materials and labor.

Net Income

The amount of money left over after all expenses and taxes have been subtracted from total revenue.