Calculating Angular Momentum: Axis of Rotation Explained

Thread starter ajaysabarish
Start date Dec 20, 2015
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Motion Newtonian mechanics Rotational Rotational dynamics Rotational motion

In summary, angular momentum is a vector quantity that describes the rotational motion of an object around a fixed axis. It is calculated by multiplying the moment of inertia by the angular velocity and is measured in kilogram-meters squared per second. The axis of rotation, which is an imaginary line perpendicular to the plane of rotation and passing through the center of mass, plays a crucial role in determining the direction of the angular velocity vector and therefore affects the angular momentum. Some real-world applications of calculating angular momentum include understanding the motion of objects in space, engineering and design, sports, and atomic and quantum physics.

Dec 20, 2015

ajaysabarish

about what axis is equation of angular momentum calculated(angular momentum = moment of inertia*angular velocity)?
please help.

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Dec 20, 2015

jedishrfu

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There is an infographic in the wiki article that shows the relationship:

https://en.wikipedia.org/wiki/Angular_momentum

in the section on: Vector — angular momentum in three dimensions

1. What is angular momentum?

Angular momentum is a physical quantity that describes the rotational motion of an object around a fixed axis. It is a vector quantity, meaning it has both magnitude and direction, and is calculated by multiplying the moment of inertia (a measure of an object's resistance to change in rotational motion) by the angular velocity (the rate of change of the angular displacement).

2. What is the axis of rotation?

The axis of rotation is an imaginary line around which an object rotates. It is perpendicular to the plane of rotation and passes through the center of mass of the object. The direction of the axis of rotation is determined by the direction of the angular velocity vector.

3. How do you calculate angular momentum?

Angular momentum is calculated by multiplying the moment of inertia of an object by its angular velocity. The moment of inertia depends on the mass and distribution of mass of the object, while the angular velocity is the rate of change of the angular displacement. The resulting unit of angular momentum is kilogram-meters squared per second (kg * m^2/s).

4. How does the axis of rotation affect angular momentum?

The axis of rotation is an important factor in calculating angular momentum because it determines the direction of the angular velocity vector. If the axis of rotation changes, the direction of the angular velocity and therefore the direction of the angular momentum will also change. This is why a change in the axis of rotation can cause a change in an object's rotational motion.

5. What are some real-world applications of calculating angular momentum?

Angular momentum is an important concept in understanding the motion of objects in space, such as planets and satellites. It is also used in engineering and design to analyze the rotational motion of machines and structures. In sports, angular momentum plays a role in activities such as gymnastics and figure skating. It is also an important concept in atomic and quantum physics, where it is used to describe the motion of subatomic particles.