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- Thread starter erocored
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Same dimension doesn't imply the same physical quantity. For energy (work) the Force [N] is parallel to the distance [m]. For torque they are orthogonal.The torque's dimension is N*m it seems like energy.

Because rotational inertia depends on the distance of the mass to the rotation axis, not just on the amount of mass.Why angular momentum is not mass times angular velocity?

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Momentum is a conserved quantity and force is its rate of transfer. Similarly angular momentum is a conserved quantity and torque is its rate of transfer.Wikipedia says that they are the equivalents of momentum and force in rotational motion but I don't understand why this comparison is possible.

Because that quantity is not conserved. Nobody cares about it.Why angular momentum is not mass times angular velocity?

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Two rotating objects can have identical mass and still show different resistances to change the magnitudes of their angular velocities.... Why angular momentum is not mass times angular velocity?

The object with more mass concentrated near the axis of rotation will have less inertia, and will increase or decrease its angular velocity more quickly under the action of an applied torque, than the object with more mass concentrated far from the axis of rotation.

The concept of

Please, see:

https://en.m.wikipedia.org/wiki/Moment_of_inertia

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In each case the ##moment## is calculated using the nearest distance to the chosen axis, because for rotation that is what is important.

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A quick trip to google suggests that the mathematical definition of "moment" is of more importance than the English dictionary definition.

In each case the ##moment## is calculated using the nearest distance to the chosen axis, because for rotation that is what is important.

https://en.wikipedia.org/wiki/Moment_(mathematics)

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Perhaps. I found it useful to know the archaic English when teaching it. Otherwise it lacks color.

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Crack a book! Torque is defined in such a way that makes it proportional to angular acceleration for a rigid body. Angular momentum is defined in such a way that makes it conserved in the absence of a net external torque. Any decent college-level introductory physics textbook will cover this in full detail.

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