Concept explainers
(a)
The orbital period of the cloud, if a gas cloud located in the spiral arm of a distant galaxy has an orbital velocity of 400 km/s while moving in a circular orbit and the distance from the center of the galaxy is 20,000 pc.
(a)
Answer to Problem 26Q
Solution:
Explanation of Solution
Given data:
For a gas cloud located in the spiral arm of a distant galaxy, the orbital velocity is
Formula used:
The expression for time taken by an object in circular motion to complete an orbit is,
Here,
Conversion from km/s to m/s is performed as,
Conversion from pc to m is performed as,
Conversion from 1 s to 1 year is performed as,
Hence,
Explanation:
Write the expression for the period of the cloud’s orbit around the galactic center.
Substitute
Further, solve as,
Conclusion:
Therefore, the orbital period of the cloud is
(b)
The mass of the galaxy contained within the cloud’s orbit, if a gas cloud located in the spiral arm of a distant galaxy has an orbital velocity of 400 km/s while moving in a circular orbit and the distance from the center of the galaxy is 20,000 pc.
(b)
Answer to Problem 26Q
Solution:
Explanation of Solution
Given data:
For a gas cloud located in the spiral arm of a distant galaxy, the orbital velocity is
Formula used:
The expression for mass of our galaxy within the cloud is,
Here,
The value of
Conversion from km/s to m/s is performed as,
Conversion from pc to m is performed as,
Explanation:
Recall the expression for mass of our galaxy within the cloud.
Substitute
Conclusion:
Therefore, the mass of our galaxy within the cloud is
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Chapter 22 Solutions
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