Angular Momentum Conservation in Gear Interactions

AI Thread Summary
In gear interactions, when a rotating gear with an upward angular momentum vector meshes with a stationary gear of the same radius and moment of inertia, the second gear's angular momentum vector points downward due to opposite rotation. This creates a scenario where one gear has positive angular momentum and the other has negative, seemingly summing to zero. However, angular momentum is not conserved in this isolated system because the axles of the gears are not included in the analysis. The axles can absorb some of the angular momentum, allowing for conservation when the entire system is considered. Therefore, the conservation of angular momentum must account for all components involved in the interaction.
george heck
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Lets say one gear is rotating with some angular velocity and its angular momentum vector is pointing up.
A second gear (not rotating) is then allowed to mesh with the first. The second gear has the same radius and moment of inertia as the first.
Is not the angular momentum vector of the second gear pointing down since it rotates opposite to the first?
and if so, how is it that angular momentum is conserved as one gear will have positive and the other negative
angualar momentum - thus summing to zero, (after the "collision")?

thanks
 
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Hint : It isn't conserved . Look at the axle of the gears . Are they part of your system ?
 

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