Exploring the Conservation of Angular Momentum in Rotating Objects

In summary, the conversation discusses the concept of potential energy and how it applies to rotating objects. Rotational energy is considered to be kinetic energy and there is no need to convert it. The energy stored in a spinning mass can be calculated using the Moment of Inertia and angular velocity. There is no potential energy stored in rotating objects, but the concept of torsion springs can be applied. Additionally, when a fast spinning object is set down, its rotation may slow down and its linear motion may speed up, but this is due to the overall system including the planet it is on.
  • #1
FallenApple
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So masses on springs store potential energy. Height in a gravational field store potential energy for the mass there.So why isn't there a potential energy stored inside rotating objects? Surely there are ways to translate the rotational energy to kinetic. Its kinda like a spring. If a set down a fast spinning object, it will roll forward slowing its rotation down and speeding up its linear motion. One type of energy is transferred to another.
 
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  • #2
FallenApple said:
potential energy stored inside rotating objects?

rotations are described by 'kinetic' state - a change of configuration so why we seek a potential energy-
potential energy is manifest in the position of bodies in a 'field'
if one is sitting at the seventh floor of a building he has a potential to do work if he falls to the ground in Earth's gravitational field- its not due to inertia of rest or motion.
if the person is spinning as well as sitting on the sae height -what additional potential he developes- added energy is best estimated by his rotational energy which is 'kinetic ' in character.
 
  • #3
FallenApple said:
Surely there are ways to translate the rotational energy to kinetic.
I don't understand. It is already kinetic.
 
  • #4
FallenApple said:
Surely there are ways to translate the rotational energy to kinetic. Its kinda like a spring. If a set down a fast spinning object, it will roll forward slowing its rotation down and speeding up its linear motion. One type of energy is transferred to another.

What Dale said. The energy rotational energy stored in a spinning mass _is_ kinetic energy. No need to "convert it".

You can calculate it as..

E = 0.5 I ω2

where
I is the Moment of Inertia (analogous to mass in a linear system)
ω is the angular velocity (analogous to velocity in a linear system)

FallenApple said:
So why isn't there a potential energy stored inside rotating objects?

See torsion spring. https://en.wikipedia.org/wiki/Torsion_spring

14154-4703257.jpg
 
  • #5
FallenApple said:
If a set down a fast spinning object, it will roll forward slowing its rotation down and speeding up its linear motion.

That might appear to be the case but you need to think about the whole system including the planet you are doing the experiment on.

If you spin up a flywheel on the surface of the Earth you affect the rotation of the planet (Newtons laws). There is no net change in the angular momentum of the combined planet/flywheel system. That's because there has been no external force applied to the system.
 

1. What is rotational potential energy?

Rotational potential energy is the energy stored in an object due to its position or orientation in a gravitational or electric field. It is the energy that an object possesses because of its potential to rotate around a fixed axis.

2. How is rotational potential energy different from linear potential energy?

Rotational potential energy is different from linear potential energy in that it is dependent on the object's rotational position or orientation, while linear potential energy is dependent on the object's linear position or height.

3. What factors affect the amount of rotational potential energy an object has?

The amount of rotational potential energy an object has is affected by its mass, distance from the axis of rotation, and the strength of the gravitational or electric field it is in.

4. How is rotational potential energy related to kinetic energy?

Rotational potential energy and kinetic energy are both forms of mechanical energy and are related through the conservation of energy principle. As an object with rotational potential energy begins to rotate, it also gains kinetic energy. As the object slows down, the kinetic energy is converted back into rotational potential energy.

5. How is rotational potential energy useful in real-world applications?

Rotational potential energy is useful in many real-world applications, such as in the design of engines and turbines, where it is converted into mechanical work. It is also important in understanding the stability and motion of objects, such as satellites and planets, in orbit around a central body.

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