Question

Question #126a1

Answer 1

You can do it like this:

Explanation:

Hooke's Law tells us that force `F` is proportional to extension `x`:

`:.F=-kx`

`k` is the force constant.

`x` is the extension.

For a spring the work done in stretching it will be converted to stored elastic potential energy.

Work done = force x distance moved in the direction of the force.

With a spring we cannot use this directly since the force is constantly changing.

We need to use a bit of calculus:

`W=intF.dx`

`:.W=-int_0^xkx.dx`

`:.W=1/2kx^2`

This gives us the stored elastic potential energy.