How is angular momentum defined in terms of moment of inertia and angular velocity?

Angular momentum is defined as the product of moment of inertia and angular velocity, L = Iω.

In the equation L = Iω, what does the symbol I represent?

I represents the moment of inertia of the rotating object.

Under what condition is angular momentum conserved in a system?

Angular momentum is conserved when no external torque acts on the system.

Why does angular velocity increase when moment of inertia decreases in an isolated rotating system?

Because angular momentum must remain constant, so a decrease in moment of inertia requires a proportional increase in angular velocity.

What happens to the angular velocity of an isolated system if its moment of inertia increases?

The angular velocity must decrease to conserve angular momentum.

How is angular impulse defined?

Angular impulse is defined as the product of torque and the time interval over which it acts.

AQA A-Level Physics 7408

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Engineering Physics

Angular momentum

4 things to know
Paper 3, section B

Overview

Conservation of angular momentum, angular impulse, and the spinning skater.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Numbers

How is angular momentum defined, and when is it conserved?

Numbers

What is angular impulse, and how does it relate to change in angular momentum?

Numbers

When does TΔt = Δ(Iω) apply, and why does a skater spin faster with arms pulled in?

Numbers

How is final angular velocity found after an impulse, and how does a gymnast use this?

Questions from this subtopic

Each one with the model answer underneath.

1
How is angular momentum defined in terms of moment of inertia and angular velocity?
Model answer
Angular momentum is defined as the product of moment of inertia and angular velocity, L = Iω.
2
In the equation L = Iω, what does the symbol I represent?
Model answer
I represents the moment of inertia of the rotating object.
3
Under what condition is angular momentum conserved in a system?
Model answer
Angular momentum is conserved when no external torque acts on the system.
4
Why does angular velocity increase when moment of inertia decreases in an isolated rotating system?
Model answer
Because angular momentum must remain constant, so a decrease in moment of inertia requires a proportional increase in angular velocity.
5
What happens to the angular velocity of an isolated system if its moment of inertia increases?
Model answer
The angular velocity must decrease to conserve angular momentum.
6
How is angular impulse defined?
Model answer
Angular impulse is defined as the product of torque and the time interval over which it acts.

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