Question about the rotating disc

  • Thread starter Fredrik
  • Start date
  • #1
Fredrik
Staff Emeritus
Science Advisor
Gold Member
10,872
418
Consider a disc in the framework of special relativity. It's initially at rest in an inertial frame, and then you get it rotating in a way that respects the symmetry of the circle (e.g. by turning a thin rod through its center). There's no way that the acceleration of the different parts of the objects can be Born rigid. Does this mean that we have to perform an amount of work that depends on the disc's elasticity to get it rotating?

I'm pretty sure that the answer is yes, but I'd like someone to confirm it or prove me wrong.
 

Answers and Replies

  • #2
Dale
Mentor
Insights Author
2021 Award
32,410
9,395
You have to perform more work than that. At a minimum there is work that goes into deformation of the material, and there is also the work on increasing the KE of the disk.
 

Related Threads on Question about the rotating disc

  • Last Post
Replies
11
Views
3K
  • Last Post
Replies
7
Views
2K
  • Last Post
Replies
3
Views
2K
Replies
1
Views
3K
Replies
80
Views
11K
Replies
10
Views
2K
Replies
4
Views
2K
  • Last Post
Replies
16
Views
4K
Replies
13
Views
909
  • Last Post
Replies
2
Views
2K
Top