**By Alexandru M 7T**

Below are the equations for spring extension under the action of a weight:

i = initial length (cm). The initial length is the original length of a spring with no weight applied on it.

e = extension per Newton (cm/N). The extension per Newton is how much a spring extends for every Newton added.

m = mass (g). Mass is the amount of grams applied to a spring that makes it extend.

G = weight (N). Weight is the force of gravity corresponding to a mass. On Earth:

G = m * 10

X = extension (cm). Extension is how much a spring extends from its initial or previous length.

X = G * e

L = total length (cm). The total length is the length of the spring when it has been extended.

L = i + X