#### Raihan amin

1. The problem statement, all variables and given/known data
A stick of length 2L and of mass M spins with angular velocity ω around the axis perpendicular to the COM of the stick.It is rotating with making an angle Θ,with the axis parallel to Z axis.The COM has an initial velocity v=υ(to the y axis).Find it's precession radius R.

2. Relevant equations.
Angular momentom L=IW
Again L=mυR and

τ=δL/δt

3. The attempt at a solution
I figure out the torque τ and the change of angular momentum .then i find the gyroscopic relationship W=mgr/Iω
Thanks.

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#### PF_Help_Bot

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#### kuruman

Homework Helper
Gold Member
A stick of length 2L and of mass M spins with angular velocity ω around the axis perpendicular to the COM of the stick.
Do you really mean to say this? The COM is a point; an axis cannot be perpendicular to it but can only pass through it. It would help if you posted a drawing showing $\vec \omega$ as a straight arrow to clarify the spin axis. Could it be that the spinning stick is to be treated as a spinning top precessing in the Earth's gravitational field? In that case one end must rest on a horizontal plane and the stick must have a non-zero moment of inertia about its axis.

#### Raihan amin

Do you really mean to say this? The COM is a point; an axis cannot be perpendicular to it but can only pass through it. It would help if you posted a drawing showing $\vec \omega$ as a straight arrow to clarify the spin axis. Could it be that the spinning stick is to be treated as a spinning top precessing in the Earth's gravitational field? In that case one end must rest on a horizontal plane and the stick must have a non-zero moment of inertia about its axis.

Sorry.here the question has some mistake itself.The right version is as follows:
The stick is spinning with angular velocity ω .And the aerodynamic lift coefficient is C. Here gravity should be neglected because the perpendicular part of lift force equate the weight of the stick.

#### Raihan amin

And density of air is ρ.

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