(adsbygoogle = window.adsbygoogle || []).push({}); [urgent] finding mass enclosed my a stars radius from center.

1. The problem statement, all variables and given/known data

the rotational speed of an orbiting object is given by v= (Gm/R)^1/2where R is distance at which the object is rotating from the center of the mass distribution and M is the amount of mass within the radius R. for the distribution in a disk, the mass enclosed increases with R^2. the sun rotates in the ids of the Galaxy at distance of 8Kpc and a speed of 220km/s find the rotational speed of a star in the disk that is located at a distance of 12Kpc from the center of Galaxy.

i have no clue how to do this question. it was on my quiz but didn't know how to do. i really need help.

2. Relevant equations

the equation is given in the question.

3. The attempt at a solution

i have no clue how to start this.

i tried using v is proportional to M/R but it does not work

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# Homework Help: Finding mass enclosed my a stars radius from center.

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