Gravuty and Conservation of Energy.

[Anjruu]

A man holds up a 100 pound weight. He applies a force to the weight of 98 Newtons to hold up the weight (f=m*a). Gravity likewise applies the same force. However, the man will eventually get tired, but gravity will not. Gravity's force is eternal. Doesn't this violate conservation of energy? The same is true of the other 3 fundamental forces.

[Cap'n Refsmmat]

To quote another person in another thread:

Force isn't work.

If the weight isn't moving, it's not work.

 

 

(sorry I can't explain it any better than that, this is just something I dug up from another thread)

[Anjruu]

Well, that's just the definition of "work," in the physics sense versus the average way it is used. Regardless, force is exerted on the weight, just the net is equal to zero. Also, the theory is conservation of energy, not work.

 

Oh, and I apologize for the "gravuty" error. "U" is pretty close to "I" on the keyboard, in my defense.

[J.C.MacSwell]

[

 

Oh, and I apologize for the "gravuty" error. "U" is pretty close to "I" on the keyboard, in my defense.

 

No bug deal

[JaKiri]

Doesn't this violate conservation of energy?

 

No, it does not.

[ydoaPs]

gravity doesn't have muscles, why would it get tired?

[swansont]

The man getting tired is an engineering limitation, not a physics one.

[Anjruu]

In that case, what is the exact definition of conservation of energy?

[radiohead]

Energy cannot be created or destroyed, only changed.

[radiohead]

I couldn't edit my post, so here is why it can't be an energy.

Gravity in a sense can be created. If you have a planet, and it starts to grow, adding more mass as it grows, more gravity will come.

I haven't studied general mechanics, so if thats wrong, just correct me...

[losfomot]

I couldn't edit my post' date=' so here is why it can't be an energy.

Gravity in a sense can be created. If you have a planet, and it starts to grow, adding more mass as it grows, more gravity will come.

I haven't studied general mechanics, so if thats wrong, just correct me... [/quote']

 

But the gravity is not being created, it is just adding up.