What is the Solution to a Rotational Motion Problem?

[coldblood]

Hi friends,
Please help me in solving this problem, I'll appreciate the help.

The problem is as:

https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-frc3/q71/s720x720/1493131_1461727260721046_949193439_n.jpg

Attempt -

https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-prn1/q71/s720x720/1524731_1461727337387705_494938793_n.jpg

Thank you all in advance.

 

[haruspex]

You forgot to convert 3000 rpm to radians/s.

 

[coldblood]

You forgot to convert 3000 rpm to radians/s.

No haruspex,

I have converted it in the second last line.
Please see.

 

[haruspex]

No haruspex,

I have converted it in the second last line.
Please see.

Looks to me like you converted rpm to revs/sec, and you converted n revolutions to 2nπ radians, but I don't see any conversion from revolution rate to radian rate. (The pi's should cancel.)

 

[coldblood]

The problem has been cleared.