Re: Elastic potential energy

[Ludwik Kowalski <kowalskiL@MAIL.MONTCLAIR.EDU>]

I have found a very unusual spring last year. The coils remain
in contact till the pulling F is about 6 N. Then the x=f(F) become
a straight line whose slope is about 50 N/m. Good for demos.
Ludwik Kowalski

Sandin wrote:

> In the 10th edition of Sears and Zemansky's University Physics, on pages
> 175 and 176 we derive the expression for the work done in stretching a
> spring from its unstretched length to a length X via calculus and
> graphically, then follow up with the work to stretch it from xsub1 to
> xsub2.
> Then on page 205, we relate the work done to the elastic potential energy,
> emphasizing the U = 1/2 kx^2 equation. However, we also show expressions
> for the change in U when x changes from xsub1 to xsub2. Also, at the
> bottom of the page in a caution, we state that "x = 0 must be the position
> at which the spring is neither stretched or compressed" in order to state
> that U = 1/2 kx^2.