# 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?

Apr 28, 2016

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: $F = m g = 8 \cdot 9.8 = 78.4$ $N$ downward

Spring force: $F = k x = 6 \cdot 3 = 18$ $N$ upward

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