What Do We Mean When We Say That the Rotation

question 88

Multiple Choice

What do we mean when we say that the rotation curve for a spiral galaxy is "flat"?

• A) Gas clouds orbiting far from the galactic center have approximately the same orbital speed as gas clouds located further inward.
• B) The amount of light emitted by stars at different distances is about the same throughout the galaxy.
• C) The disk of a spiral galaxy is quite flat rather than spherical like the halo.
• D) All the galaxy's mass is concentrated in its flat, gaseous disk.

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Definitions:

Tracheae

Tubes in the respiratory system that conduct air to and from the lungs.

Book Lungs

Respiratory organs found in certain arachnids, such as spiders and scorpions, consisting of stacked leaf-like structures used for gas exchange.

Malpighian Tubules

Excretory structures in insects and some arthropods that remove metabolic wastes from the body into the digestive tract for excretion.

Tympanum

The eardrum, a thin membrane that vibrates in response to sound waves, playing a key role in the hearing process.