Work done aginst conservative force!!!

[peacefulheart]

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"The work done against conservative forces is conserved in potential energy"

what does " the work done against conserve forces" mean? I know the net work done by conserve force in a closed path is conserved.


thanks a lot !

 

[EnergyDrink]

A conservative force is a force that is constant, usually referring to gravity. Work done against gravity (lifting) is conserved in potential energy.

In a non-conservative force, this is not the case, for example, friction. Work done against friction is not conserved.

 

[milski]

It does not matter if the force is constant or not. Gravity is not constant at planetary scale but still remains conservative. The definition is that for conservative forces the work needed to move an object from point A to point B does not depend on the path taken between A and B.

If you move an object 10 m up, you'll always have to do 10*mg J of work - regardless if you're lifting it straight up, or pushing it up on a frictionless ramp or taking any arbitrary path. That's not true when talking about work done by friction - here, the longer the path is, the more work is being done.

Gravity and electrostatic forces are the typical conservative forces that you'll encounter for MCAT purposes.