A Radio Astronomer Points a Radio Telescope Through the Milky

question 205

Multiple Choice

A radio astronomer points a radio telescope through the Milky Way's disk in a direction directly away from the center of the Galaxy.If the astronomer measures the Doppler shift of the 21-cm radio line of hydrogen from interstellar clouds at several different distances from the Sun along this line of sight,what should be the result? (Figure 13-7 of Comins,Discovering the Essential Universe,6th ed.,may be helpful.)

• A) The Doppler shift should have a constant value, regardless of distance, as a result of the Sun's speed of motion around the center of the Galaxy.
• B) The Doppler shift should be almost zero for all clouds, regardless of distance.
• C) The Doppler shift should rise to a maximum at some distance, then decrease again.
• D) The Doppler shift should be larger the farther away the cloud is.

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Definitions:

Self-schema

A cognitive representation of oneself that organizes and guides the processing of self-related information.

Declarative

Pertaining to knowledge that can be consciously recalled and articulated, such as facts or information.

Procedural

refers to a method or process in the execution of actions or operation of systems, often opposed to declarative knowledge which is about facts or things known.

Self-efficacy

An individual’s belief in their capacity to execute behaviors necessary to produce specific performance attainments, shaping how they think, feel, and act.