Determining the precession radius

In summary, the stick is spinning and it has an aerodynamic lift coefficient. The perpendicular part of the lift force is equal to the weight of the stick, and the density of air is ρ.
  • #1
Raihan amin
46
0

Homework Statement


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.

Homework Equations

.
Angular momentom L=IW
Again L=mυR and [/B]
τ=δL/δt

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
Please help me to find the things out.
Thanks.[/B]
 

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  • #2
Raihan amin said:
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.
 
  • #3
kuruman said:
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.
 
  • #4
And density of air is ρ.
 

What is precession radius?

The precession radius is the distance from the rotational axis of a spinning object to the point where its spin axis intersects with a reference plane. It is a measure of the amount of precession, or change in the orientation of the spin axis, of the object.

How is precession radius determined?

The precession radius can be determined through various methods, such as using a gyroscope or measuring the angle of precession, which is the angle between the spin axis and the reference plane. It can also be calculated using the object's moment of inertia, angular velocity, and angular momentum.

What factors affect the precession radius?

The precession radius is affected by the object's moment of inertia, angular velocity, and angular momentum. It is also influenced by external forces such as gravity and friction, which can cause changes in the object's spin axis and therefore affect the precession radius.

Why is precession radius important?

The precession radius is important in understanding the behavior of spinning objects, such as planets and gyroscopes. It can also be used in various applications, such as navigation and engineering, where precise measurements of precession are necessary.

Can precession radius be negative?

Yes, precession radius can be negative if the spin axis of the object is tilted in the opposite direction from the reference plane. In this case, the precession radius would be measured as a negative value, indicating a backward precession.

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