# Some Explanation with Rigid Rotator

1. Nov 21, 2009

### firoz.raj

Can anybody explain me .About Rigid Rotator.Kindly let me know the idea.Any help would be
highly appreciated.

2. Nov 22, 2009

### Danger

I doubt that I can be of any help to you, but I have a request for clarification. Are you referring to a helicopter rotor set, or something else?

3. Nov 22, 2009

### tiny-tim

Welcome to PF!

Hi firoz.raj! Welcome to PF!

Yes, you really do need to be more specific.

What do you mean by "Rigid Rotator"?

4. Nov 22, 2009

### firoz.raj

Re: Welcome to PF!

i need to Understood the following Expression.Kindly let me know step by step.

#### Attached Files:

• ###### RigidRotator.jpg
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5. Nov 22, 2009

### tiny-tim

ok, I understand now.

"rigid rotor" simply means that r is constant, and only θ and φ vary.

So when we transform from Cartesian to polar coordinates, ∂/∂r = zero, and every ∂/∂r can be omitted, leaving only ∂/∂θ and ∂/∂φ, as shown in your picture.

6. Nov 22, 2009

### firoz.raj

rigid rotor" simply means that r is constant, and only θ and φ vary.

Sir,
i need to Give BS(Physics) Final Year examination.i think this is not a Appropriate Explanation
in My Case.Simple r is Const.and only θ And φ will be vary.i need Good Explanation.Sorry this
is really small question but i will ask.Additional if possible kindly tell me any example also for
Rigid Rotator.