- #1
adjacent
Gold Member
- 1,553
- 63
As we all know,Potential energy =mgh.If someone digs a hole and place a ball at 0 height,the potential energy should be zero but it falls somehow.How is this possible?
As we all know,Potential energy =mgh.If someone digs a hole and place a ball at 0 height,the potential energy should be zero but it falls somehow.How is this possible?
The point at which potential energy is zero is completely arbitrary and hence has no special meaning. All that matters how potential energy changes. Adding an arbitrary constant to some potential function has no impact on those changes in potential. You could make the potential at infinity be the zero point, and then anything at a finite distance will have a negative potential. In fact, making the zero be at an infinite distance is a very widely used choice for gravitational potential energy.I think the zero point should be the center of the earth.If I keep a ball on the ground,we can say it has no potential energy because of zero height.If I suddenly dig a hole,the ball suddenly gains potential energy?This is confusing
I think the zero point should be the center of the earth.
Sure it is. You haven't taken Newton's shell theorem into account.And that ##1/r## term means that you cannot use the center of the earth as the zero point - the potential isn't even defined there.
Sure it is. You haven't taken Newton's shell theorem into account.