# Superposition of SHM

1. Jul 18, 2015

### andyrk

Why do we simply add the equations of SHM in case the two SHMs are superimposing?

2. Jul 18, 2015

### Staff: Mentor

Are you familiar with the differential equation that describes a system undergoing simple harmonic motion, $x''=-kx$? If $x=A(t)$ and $x=B(t)$ are both solutions of that differential equation, then $x(t)=A(t)+B(t)$ is also a solution.

3. Jul 18, 2015

### Staff: Mentor

Because the differential equation is linear.

Chet