An object with a mass of 4kg is hanging from a spring with a constant of 3kgs2. If the spring is stretched by 12m, what is the net force on the object?

2 Answers
Jul 11, 2017

The net force is =3.2N acting downwards

Explanation:

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The mass is m=4kg

The spring constant is k=3kgs2

The extension is x=12m

Resolving in a vertical direction +

The net force is

F=kxmg

=31249.8

=3.2N

Jul 11, 2017

The net force should ideally be zero

Explanation:

The object hanging by the spring is acted on by two forces.The gravitational force pulls its down while the spring resists this.

The force exerted by spring is given by Hooke's law as follows Fs=kx where k is referred to as Hooke's constant and x is the displacement.Substituting for values we have Fs=312=36N

The gravitational force is given by the equation Fg=mg which when substituted gives Fg=4kg9.8ms2=39.2N
In a state of equilibrium Fs should be equal to Fg.