Parallel and Series Springs

Oscillation frequency of mass m on a spring with spring constant k:

If two springs with spring constants k₁ and k₂ are in parallel, connected side by side and one end of the springs is fixed on a rest wall and the other end is fastened to some mass, 

then together they affect to the mass as one spring with a spring constant k

k = k₁ + k₂.

If two springs with spring constants k₁ and k₂ are are in series, connected not side by side but one by one,

then they affect to the mass as one spring with a spring constant k obtained from the equation:

1/k = 1/k₁ + 1/k₂.

---------