Springs question -- vertical versus horizontal stretching... So I know hooke's law well enough and I understand the spring constant and it's vertical applications where force equals displacement times some constant. What I am unsure of is to what degree this all applies to a horizontal stretch of a string? For one scenario let's say our spring of constant k is bound at both ends and is stretch sideways, whats the relationship between the constants and the tensile force drawing the spring back? For the second scenario lets say we leave one end dangling of a slinky and pull it at 1/2 the length, how does the original spring constant change between the two divisions? Lastly, given a slinky, what effects on tension are we looking at if we twisted it? You can watch some pretty nifty tensile responses from coiling a slinky beyond what it's equilibrium state is and im very curious about this. What does it doto the spring constant? Are there localized regions of stress for any particular reason or is it manufacturer inconsistency?