Conservation of angular momentum - change of inertia

In summary, conservation of angular momentum refers to the principle that states the total angular momentum of a system remains constant unless an external torque is applied. This means that if there are no external forces acting on a rotating object, its angular momentum will remain the same. This principle is closely related to the concept of inertia, which refers to an object's resistance to changes in its state of motion. Therefore, when the inertia of an object changes, its angular momentum will also change, leading to a corresponding change in its rotational speed. Conservation of angular momentum is an important concept in physics and is used to explain various phenomena, such as the behavior of rotating objects in space and the motion of planets around the sun.
  • #1
Asgrrr
Recently I was searching the internet and books for the connection between conservation of angular momentum and conservation of rotational energy and found nothing. Let's say an ice skater rotates and draws the arms in - the rotation speeds up. The rotational energy must increase because the linear velocity of every particle is increased.

I think I managed to prove that the work required to draw in the arms is equal to the increase in rotational energy. Could this be correct?
 
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  • #2
Sure - work has to come from somewhere. In this case it's the skater's muscles.
 

Related to Conservation of angular momentum - change of inertia

1. What is conservation of angular momentum?

Conservation of angular momentum is a fundamental principle in physics that states that the total angular momentum of a system remains constant in the absence of external torques. This means that the total amount of rotational motion in a system will remain the same unless an external force is applied.

2. How does angular momentum relate to inertia?

Angular momentum and inertia are closely related as inertia is the measure of an object's resistance to changes in its rotational motion, and angular momentum is a measure of the rotational motion itself. In other words, the more inertia an object has, the more angular momentum it will have.

3. Can the angular momentum of a system change?

Yes, the angular momentum of a system can change if external forces or torques are applied. However, the total angular momentum of the system will remain constant, as stated by the conservation of angular momentum principle.

4. What is the formula for calculating angular momentum?

The formula for angular momentum is L = Iω, where L is the angular momentum, I is the moment of inertia, and ω is the angular velocity. Alternatively, it can also be written as L = r x p, where r is the distance from the axis of rotation to the object and p is the linear momentum.

5. How is conservation of angular momentum applied in real-life situations?

Conservation of angular momentum is a crucial concept in many real-life situations, such as in the motion of planets and satellites, the movement of spinning objects like tops and gyroscopes, and even in sports like ice skating and figure skating. It is also important in engineering and technology, such as in the design of spacecraft and satellites.

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