2 Accelerating Rotational Points in One System

AI Thread Summary
The discussion revolves around a mechanical system involving a 2D circle with a mass attached to a fixed point via a rod, and a rocket exerting a tangential force. Participants are trying to determine how to calculate the total system energy over time, considering the complexities of rotational motion. Key points include the need to analyze the rotational kinetic energy for each axis of rotation, which are not perpendicular. There is also a consideration of how the rocket's force can affect the system's motion, potentially slowing it down. The conversation highlights challenges in visualizing the mechanics of the system and the appropriate classification of the topic within physics.
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A 2 dimensional circle of radius "r" and mass "m" is attached through the center of the circle by a rigid, massless rod to a fixed point of rotation a distance "l" away. A massless rocket is attached to the outside of the circle a height of 0 away from the circle's surface and "r" away from the circle's center. The rocket exerts a constant force "F" tangentially to the circle. The system is ideal. How would I go about finding the total system energy with respect to time?
 
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I realize it's mechanics, but does this really belong in introductory physics?
 
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Mechanics said:
A 2 dimensional circle of radius "r" and mass "m" is attached through the center of the circle by a rigid, massless rod to a fixed point of rotation a distance "l" away. A massless rocket is attached to the outside of the circle a height of 0 away from the circle's surface and "r" away from the circle's center. The rocket exerts a constant force "F" tangentially to the circle. The system is ideal. How would I go about finding the total system energy with respect to time?

If I'm visualizing this correctly, we have two axes of rotation at right angles. You should be able to work out the rotational kinetic energy for each rotation individually. How do you add the kinetic energies in this case? (Hint: Is kinetic energy a scalar or a vector?)

-Dan
 
Dan, the axes of rotation are not at right angles to each other. The circle is free to rotate around its center and the fixed point at the end of the rod a distance "l" from the center of the circle. The rocket will also at times be slowing down the system as the periods about each axes of rotation is not necessarily the same so the force will at times be in the direction opposite to the motion.
 
Mechanics said:
Dan, the axes of rotation are not at right angles to each other. The circle is free to rotate around its center and the fixed point at the end of the rod a distance "l" from the center of the circle. The rocket will also at times be slowing down the system as the periods about each axes of rotation is not necessarily the same so the force will at times be in the direction opposite to the motion.

Hmmm...not seeing it. I must not be visualizing it right. Ah well, that was never one of my strong points...I guess someone else better take it from here.

-Dan
 
If no one here can help me solve it, can this thread be moved back to Classical Physics where I posted it?
 

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