If We Found a Star Cluster at the Edge of the Disk

question 90

Multiple Choice

If we found a star cluster at the edge of the disk of the Milky Way at a distance of 10 kpc from the center, and it orbited with a velocity of 250 km/s, what would be the total mass enclosed within this radius?

• A) 1.4 * 10¹¹ M_SUN
• B) 7.2 * 10¹¹ M_SUN
• C) 9.5* 10¹¹ M_SUN
• D) 4.2 * 10¹² M_SUN
• E) 8.0 *10¹² M_SUN

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Definitions:

Intercalated Discs

Specialized junctions between cardiac muscle cells that facilitate the synchronized contraction of the heart.

Excitation-Contraction Coupling

The physiological process of converting an electrical stimulus to a mechanical response, essential for muscle contraction.

Action Potential

A rapid and temporary electrical charge that travels along the membrane of a neuron, initiating the transmission of a nerve impulse.

Sarcolemma

The thin, plasmalemma (plasma membrane) surrounding a muscle fiber, crucial for transmitting signals and coordinating contractions.