# 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  14 m, what is the net force on the object?

Mar 28, 2017

The net force is $= 47.6 N$

#### Explanation:

Let's resolve in the vertical direction ${\uparrow}^{+}$

mass, $m = 8 k g$

spring constant, $k = 9 k g {s}^{-} 2$

extension of the spring, $x = 14 m$

${F}_{1} = k x = 9 \cdot 14 = 126 N$

${F}_{2} = - 8 g = - 78.4 N$

The net force is

$F = {F}_{1} + {F}_{2} = 126 - 78.4 = 47.6 N$

The force is acting upwards.