Question

An object with a mass of `8 kg` is hanging from a spring with a constant of `9 (kg)/s^2`. If the spring is stretched by `1 m`, what is the net force on the object?

Answer 1

Recall,

`F_"s" = -kDeltax`, and

`SigmaF = ma`

When a spring is stretched, it has elastic potential energy. In this situation, it is working against gravity in the opposite direction (which we'll assume is positive).

Hence,

`SigmaF = kDeltax - mg approx -70"N"`

is the net force on the object.