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(New tips are continually added to these pages.  Check back in a few months' time for more)

TOPIC 6:    Elasticity

Tip 1:

A steel wire behaves like a spring and has its own "spring constant".  Let's derive the "spring constant" of a steel wire.

Starting from Young's Modulus, E = Fl/Ae, by rearranging the variables, we end up with F = (EA/l)e.

If we compare this with the spring's equation, F = ke, we see that the "spring constant" of a steel wire is EA/l.

Since energy stored in a spring W = 1/2 k e2 , we can similarly write: energy stored in a stretched steel wire W = 1/2 (EA/l) e2

Unlike in a spring, which is easily stretched, it would take a very strong man (like superman) to make a noticeable stretch on a steel wire.

 

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