Power supplied holding a mass suspended in air

  • Thread starter Thread starter piisexactly3
  • Start date Start date
  • Tags Tags
    Air Mass Power
Click For Summary

Homework Help Overview

The discussion revolves around the concept of power in the context of holding a mass suspended in air. Participants are exploring the relationship between force, velocity, and power, particularly when the object is not moving.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to apply equations related to power and work but struggles with the implications of a stationary object. Some participants question the need for power when an object is held in place, while others discuss the distinction between physical work and the energy required by muscles to maintain a position.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of power and work. Some guidance has been offered regarding the application of equations, but there is no explicit consensus on the underlying concepts.

Contextual Notes

Participants are grappling with the definitions of work and power, particularly in the context of static versus dynamic scenarios. There is a recognition of the physical effort involved in holding a mass, despite the lack of movement.

piisexactly3
Messages
36
Reaction score
0
A problem I thought would be very simple, but can't seem to get very far with.

Taking equations from textbook: Fv = P . Nope because velocity is 0 however power cannot be 0.
Using suvat: W = Fs , s = ut + .5gt^t , therefore P = Fgt/2 , this seems like the equation for how power would increase as an object falls but not the power supplied to keep it suspended which I imagine would be constant with time.

So there it is, leaving me very fustrated as it seems like it must be really simple.
 
Physics news on Phys.org
Yes. Power=Fv and if it's velocity is changing(Accelerating at g), it's power should also change.I don't think I understood you r question clearly. We don't need power,not even energy to hold things in place. Consider a book lying at rest on a table. No work is done there.

Edit. You can still use that equation. Since no distance is traveled when it's suspended, you can just plug in 0 into s in P=Fs/t
 
Ok but hold 50 kilos out in front of you and tell my why its tiring but no work is being done?
 
piisexactly3 said:
Ok but hold 50 kilos out in front of you and tell my why its tiring but no work is being done?
Tiring and work done are two different things.
Our bodies are not efficient. We even get tired sitting somewhere without moving.
Muscle cells in our body need constant supply of energy to stay contracted(Which keeps things lifted up) On the other hand, the table does not deform to keep things above the ground.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
6K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 31 ·
2
Replies
31
Views
6K
  • · Replies 17 ·
Replies
17
Views
4K
Replies
12
Views
3K
  • · Replies 11 ·
Replies
11
Views
3K
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K