To my knowledge I assume:(adsbygoogle = window.adsbygoogle || []).push({});

Newton's second law of motion :

F = ma = mx''

Hooke's Law

F = ks where s is the distance displaced by the mass.

When a mass is attached to the spring, the new spring force is:

F = k(s+x)

While the downward force is still:

mg

If the two forces are equal and opposite, then:

mg = k(s+x) after simplifying

kx=0

***********************

My question is: From kx=0, how do I get:

F=kx

I know how this leads to the final equation mx''-kx=0

But do we just assume that kx is a force and set it equal to F. I just don't understand the reasoning.

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# 2nd Order Linear - Modeling Spring Oscillation

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