Constant Force: Energy Conservation & Path Independence

[harambe]

I had an argument with my friend regarding constant forces.He said that work done by constant forces are conservative as we can take the force out of the integral and it doesn't depend on the path .But the fact that this information is not given in my textbook as well as by teachers makes me doubt it. Do Constant forces conserve mechanical energy at every case and are really path independent

 

[sophiecentaur]

I had an argument with my friend regarding constant forces.He said that work done by constant forces are conservative as we can take the force out of the integral and it only depends on the path .But the fact that this information is not given in my textbook as well as by teachers makes me doubt it. Do Constant forces conserve mechanical energy at every case and are really path independent

I think that's far too much of a generalisation. Pushing against a constant friction force (a common situation) is hardly conservative.

 

[harambe]

So being a constant force doesn't mean that it is conservative right then?

Also friction would probably change direction at different paths so will it be alright to call it constant force for this case

 

[weirdoguy]

He said that work done by constant forces are conservative as we can take the force out of the integral and it only depends on the path .

By definition, work done by conservative forces should not depend on the path.

 

[harambe]

That would be my mistake...Sorry

 

[Dale]

Do Constant forces conserve mechanical energy at every case and are really path independent

A force that is constant for all paths does conserve energy. The reason the friction force mentioned by @sophiecentaur is not conservative is that it is only constant if the path is straight. It is not constant for other paths.

 

[harambe]

So as long as the constant force is constant for every path then it will be able to conserve energyThanks .I get it now