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

[Dr Moriarty]

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...

 

[lendav_rott]

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.

 

[Dr Moriarty]

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).

 

[tiny-tim]

Welcome to PF!

Hi Dr Moriarty! Welcome to PF!

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.