Potential energy of solids in tension question

AI Thread Summary
The discussion revolves around the confusion regarding the interatomic potential energy graph in relation to tension and compression in materials. The original poster notes that while the graph indicates potential energy reaches zero when bonds break under tension, it also suggests that compression could similarly lead to zero potential energy. This creates confusion, especially when considering elastic materials, where stretching increases potential energy until the material snaps. The poster seeks clarification on the relationship between potential energy, tension, and compression, questioning whether their understanding of the concepts is flawed. The discussion highlights the complexities of interpreting potential energy graphs in the context of material behavior under different forces.
beckett
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Hi folks and happy new year,

As usual i have been leafing through some old physics books and have stumbled across something that has confused me, wonder if you can help. Having looked at a 'classical' graph of interatomic potential energy against distance within a solid and how it relates to hookes law etc i realize that it doesn't completely make sense to me:


potential
|
| x
| x
| x
| x
| x
|----x(0)-------------------x(0)--------- distance
| x xxxxxxxxxx
| x xxx
| x x
| x x
| x
|
|

From this poor representation the book described the fact that when the material is placed in tension, eventually the bonds break and there is zero potential. This makes sense. What is confusing me is when i imagine the material being placed in compression because according to the graph it suggests that by doing this you can also reach zero potential. The more i think about this the more i get confused. If i imagine stretching a piece of elastic, the potential energy must increase as the graph suggests but at the same time it tends towards zero i.e the elastic snaps?? Please help me here or am i being really stupid??
 
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Sorry folks, looks like the ASCII art didn't come out as i had drawn it. Have a look at the attached image if your interested, cheers.
 

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