Symbols in the equation relating work, force, and distance moved

AI Thread Summary
The discussion centers on the equation for work, W = Fd, where the user questions whether it should instead be W = Fs, emphasizing displacement over distance. They argue that using 'd' for distance may lead to misconceptions, especially in scenarios like circular motion where total energy expended could be misrepresented as zero. Another participant clarifies that the correct formulation is W = ∫ F · ds, which accounts for varying force and direction. They note that W = Fd is a simplification applicable only in specific cases. The conversation highlights the importance of precise terminology in physics.
Dr Moriarty
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I have been taught that work = force x distance moved in direction of force, or

W=Fd

However, should this not be W=Fs, as what is really meant is displacement (s), not distance (d)?

Thank you - I sense that this is something the real Dr Moriarty would have known...
 
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If you move in a circular trajectory on your bicycle. Do you mean to say that the total energy you have spent is 0?

I have been taught that A = Fs aswell, s is the distance traveled by the influence of the Force, so it would make no sense if the summarum is 0.
 
My question is less about the actual physics, and more about the convention - it seems to me that writing W=Fd is inaccurate, as d represents distance, not displacement (s).
 
Welcome to PF!

Hi Dr Moriarty! Welcome to PF! :smile:
Dr Moriarty said:
I have been taught that work = force x distance moved in direction of force, or

W=Fd

However, should this not be W=Fs, as what is really meant is displacement (s), not distance (d)?

The correct equation is W = ∫ F · ds

(since neither the force nor the direction of motion need be constant).

W = Fd is just a simplification which applies in some circumstances. :wink:
 
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