Physics Homework Help of converting to years (astronomy q)

[Ella1777]

A star is 3.7 x 104 ly (light-years) from the center of its galaxy and is moving in a circle around that center at a speed of 170 km/s. (a) How long does it take the star to make one revolution about the galactic center? (b) How many revolutions has the star completed since it was formed about 4.2 x 109years ago?2. 2pi x light years x 1 light year
x31536000?3. for part a I did
2pi x (3.7x10^14) x 1 light year= 232477.856
232477.856/170= 410255040 years which is correct butI's stuck on part b
I did
Here's b)
(4.2 x 10^9) / 410255040 = 10.2375349
How would I convert it to the years it's asking for?
Would I just times it by 31536000?
Thank You!

 

[haruspex]

2pi x (3.7x10^14)

10⁴, right?

2pi x (3.7x10^14) x 1 light year= 232477.856

You didn't do the conversion to km, so the units are still ly.

232477.856/170= 410255040 years

Umm... no, but I guess you mean 232477.856 ly * (xxxx km/ly) /(170km/s) / (yyyy s/year) = 410255040 years.

How would I convert it to the years it's asking for?

It is not asking for a number of years:

How many revolutions has the star completed

 

[Ella1777]

10⁴, right?

You didn't do the conversion to km, so the units are still ly.

Umm... no, but I guess you mean 232477.856 ly * (xxxx km/ly) /(170km/s) / (yyyy s/year) = 410255040 years.

It is not asking for a number of years:

This has been solved hours ago on my own I was right and correct I'm just tired sometimes I even forget what the question is asking. I was tired but I got it correct it was just a blank out moment. That's why this post has been marked as solved no more assistance is needed but thanks anyways