Gyroscope Angular Speed Calculation

[MozAngeles]

Homework Statement

The rotor (flywheel) of a toy gyroscope has mass 0.150 kg. Its moment of inertia about its axis is 1.20*10^- 4 kg m^2. The mass of the frame is 2.70×10−2 kg. The gyroscope is supported on a single pivot with its center of mass a horizontal distance of 4.00 cm from the pivot. The gyroscope is precessing in a horizontal plane at the rate of one revolution in 2.40 s.
Find the angular speed with which the rotor is spinning about its axis, expressed in rev/min.

Homework Equations

$$\omega$$=(weight force*radius)/(moment of interia*$$\Omega$$)

The Attempt at a Solution

$$\omega$$= (1.73*.04)/(1.20*10^-4 *4.8)= 38 rad/s
the result is wrong. i have no idea what i am doing wrong.
any help would be nice thanks =)

 

[Quinzio]

Sure, there are 3/4 mistakes in your formula.
You need to methodically write down the basic equations of the gyro, and all your data, in a neat Latex code.

You should get 221 rad/s, or 2111revs/min, if I'm not wrong.
A typical toy gyro can spin up to 3/4000 revs/min, so it makes sense (I have one toy gyro).