Question

If the length of a `23 cm` spring increases to `82 cm` when a `5 kg` weight is hanging from it, what is the spring's constant?

Answer 1

I got `k=83N/m`

Explanation:

In this type of problems you need to use Hooke's !aw and Newton's second law:

We can write:
`-kx-mg=0`
But the elongation (in meters), according to our coordinate system, is negative so we get:
`-k(-0.59)-(5*9.81)=0`
`k=(5*9.81)/(0.59)=83N/m`