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

question 35

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,which orbited with a velocity of 300 km/s,what would be the total mass enclosed within this radius?

• A)3 × 10¹¹ M_⨀
• B)7 × 10¹¹ M_V
• C)2 × 10¹¹ M_⨀
• D)4 × 10¹² M_⨀
• E)8 × 10¹² M_⨀