If the Rotational Speed of the Gas in the Disk $\odot$

question 43

Essay

If the rotational speed of the gas in the disk of a spiral galaxy is 100 km/s at a distance of 26,000 light-years from its center, then what is the mass enclosed within this radius? If the mass of luminous matter inside this radius is 5 billion M _$\odot$ then what fraction of the galaxy's mass is made of dark matter?

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Definitions:

Dorsal Root

A cluster of sensory nerve fibers located on the dorsal side of the spinal cord, which carries sensory information to the brain.

Sensory Cortex

Part of the brain responsible for receiving and interpreting sensory information from different parts of the body.

Corticospinal Tract

A collection of neurons in the brain that project to the spinal cord and are involved in motor control.

Lateral Spinothalamic Tract

A neural pathway in the spinal cord responsible for transmitting pain and temperature sensations to the brain.