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Amru123
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I remember my teacher saying it to be the axis along the centre of mass but the centre of mass has all the mass concentrated in it and hence moment of inertia should increase as moment of inertia is proportional to mass?
I'm not sure what this is meant to mean. The mass of a body is the same whatever axis you rotate it about. Why would it change?Amru123 said:the centre of mass has all the mass concentrated in it
Yeah,he did mention.Centre of mass is where the all the mass is assumed to be concentrated.Just look up for it's definition.Ibix said:I'm not sure what this is meant to mean. The mass of a body is the same whatever axis you rotate it about. Why would it change?
Did your teacher mention the parallel axis theorem? https://en.m.wikipedia.org/wiki/Parallel_axis_theorem
Mass contributes to moment of inertia no matter where your axis is - but mass closer to the axis contributes less (it scales with the squared radius), so a lot of mass close to the axis leads to the smallest moment of inertia. Anyway, you cannot replace an object by a point-mass if you want to calculate its moment of inertia, as discussed in the previous post.Amru123 said:I remember my teacher saying it to be the axis along the centre of mass but the centre of mass has all the mass concentrated in it and hence moment of inertia should increase as moment of inertia is proportional to mass?
Moment of inertia is a physical property of a body that measures its resistance to rotational motion about a specific axis.
Moment of inertia is calculated by taking the sum of mass of each particle in the body multiplied by the square of its distance from the axis of rotation.
The moment of inertia of a body is important because it affects its rotational motion and stability. It also determines the amount of torque needed to cause a certain amount of angular acceleration.
The distribution of mass in a body greatly affects its moment of inertia. A body with most of its mass concentrated closer to the axis of rotation will have a smaller moment of inertia compared to a body with the same mass but with the mass distributed farther from the axis.
The moment of inertia of a body can vary depending on the choice of axis. It is important to choose the axis that makes the calculation simpler and easier, and also to take into account the distribution of mass in the body.