Question

If the length of a `49 cm` spring increases to `84 cm` when a `5 kg` weight is hanging from it, what is the spring's constant?

Answer 1

`140"N/m"`

Explanation:

Hooke's Law states that:

`F=-kx`

`x` is the extension which is `0.84-0.49=0.35"m"`

The force `=mg=5xx9.8"N"`

`:.k=F/x=(5xx9.8)/0.35=140"N/m"`