If the length of a 13 cm13cm spring increases to 45 cm45cm when a 4 kg4kg weight is hanging from it, what is the spring's constant?

1 Answer
Jul 1, 2018

122.5122.5 newtons per meter.

Explanation:

We use Hooke's law, which states that,

F=kxF=kx

where:

  • FF is the force applied in newtons

  • kk is the spring's constant

  • xx is the extension in meters

Here we have x=45 \ "cm"-13 \ "cm"=32 \ "cm"=0.32 \ "m", F=4 \ "kg"*9.8 \ "m/s"^2=39.2 \ "N".

So, the spring's constant is:

k=F/x

=(39.2 \ "N")/(0.32 \ "m")

=122.5 \ "N/m"