Can Rotating Objects Store Potential Energy Like Springs?

Click For Summary

Discussion Overview

The discussion centers on the concept of potential energy in relation to rotating objects, comparing it to the potential energy stored in springs and gravitational fields. Participants explore whether rotational energy can be considered a form of potential energy and how it relates to kinetic energy during motion.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions why rotating objects do not store potential energy like springs or masses in a gravitational field, suggesting that rotational energy can be translated into kinetic energy.
  • Another participant argues that rotational energy is already a form of kinetic energy and questions the need to classify it as potential energy, emphasizing that potential energy is associated with the position of bodies in a field.
  • A later reply reiterates that rotational energy is kinetic and does not require conversion, providing a formula for calculating rotational kinetic energy.
  • One participant introduces the concept of a torsion spring as a potential example of rotational energy storage.
  • Another participant highlights the importance of considering the entire system, including the Earth, when discussing the effects of spinning objects, referencing Newton's laws regarding angular momentum.

Areas of Agreement / Disagreement

Participants express differing views on whether rotational energy can be classified as potential energy, with some asserting it is purely kinetic. The discussion remains unresolved, with multiple competing perspectives present.

Contextual Notes

Participants do not fully agree on the definitions and implications of potential versus kinetic energy in the context of rotating objects, leading to a lack of consensus on the topic.

FallenApple
Messages
564
Reaction score
61
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.
 
Physics news on Phys.org
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.
 
FallenApple said:
Surely there are ways to translate the rotational energy to kinetic.
I don't understand. It is already kinetic.
 
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
 
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.
 

Similar threads

  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 54 ·
2
Replies
54
Views
7K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
6
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K