Question

An object with a mass of `8` `kg` is hanging from a spring with a constant of `9` `kgs^-2`. If the spring is stretched by `3` `m`, what is the net force on the object?

Answer 1

The net force acting will be `78.4-18=60.4` `N` downward.

Explanation:

If we assume the spring is stretched downward, there are two forces acting on the mass: its weight force due to gravity acting downward and a spring restoring force acting upward.

Weight force: `F=mg=8*9.8=78.4` `N` downward

Spring force: `F=kx=6*3=18` `N` upward

The net force acting, therefore, will be `78.4-18=60.4` `N` downward.