Anjruu Posted July 14, 2005 Share Posted July 14, 2005 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. Link to comment Share on other sites More sharing options...
Cap'n Refsmmat Posted July 14, 2005 Share Posted July 14, 2005 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) Link to comment Share on other sites More sharing options...
Anjruu Posted July 14, 2005 Author Share Posted July 14, 2005 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. Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted July 14, 2005 Share Posted July 14, 2005 [ Oh, and I apologize for the "gravuty" error. "U" is pretty close to "I" on the keyboard, in my defense. No bug deal Link to comment Share on other sites More sharing options...
JaKiri Posted July 14, 2005 Share Posted July 14, 2005 Doesn't this violate conservation of energy? No, it does not. Link to comment Share on other sites More sharing options...
ydoaPs Posted July 14, 2005 Share Posted July 14, 2005 gravity doesn't have muscles, why would it get tired? Link to comment Share on other sites More sharing options...
swansont Posted July 14, 2005 Share Posted July 14, 2005 The man getting tired is an engineering limitation, not a physics one. Link to comment Share on other sites More sharing options...
Anjruu Posted July 14, 2005 Author Share Posted July 14, 2005 In that case, what is the exact definition of conservation of energy? Link to comment Share on other sites More sharing options...
radiohead Posted July 15, 2005 Share Posted July 15, 2005 Energy cannot be created or destroyed, only changed. Link to comment Share on other sites More sharing options...
radiohead Posted July 15, 2005 Share Posted July 15, 2005 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... Link to comment Share on other sites More sharing options...
losfomot Posted July 15, 2005 Share Posted July 15, 2005 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. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now