# An object with a mass of 7 kg is hanging from a spring with a constant of 2 (kg)/s^2. If the spring is stretched by  2 m, what is the net force on the object?

Jun 11, 2018

The net force applied on the object is $64.6$ newtons.

#### Explanation:

The net force acting on the object represents the sum of all the forces which act upon it; in our case, it is

$F = G - {F}_{e}$

Where $F$ is the net force, $G$ is the gravity force and ${F}_{e}$ is the force of elasticity, also called the tensile force.

$G = m g = 7 \cdot 9.8 = 68.6 \text{ N}$

$F = k x$

Note: $k$ is the spring constant and $x$ is the displacement (how much the spring is getting stretched).

${F}_{e} = 2 \cdot 2 = 4 \text{ N}$

Hence,

$F = 68.6 - 4 = 64.6 \text{ N}$