Engineering Physics

14.1 Superposition of waves

The principle of superposition of waves states that the resultant displacement at a point in a medium is the algebraic sum of the displacements due to individual waves passing through that point simultaneously. Superposition takes place when two or more waves pass through a point in a medium.

To understand superposition, we consider two waves passing through a point in a medium. Let y₁ be the displacement of a particle at that point due to the first wave in the absence of second wave and y₂ be the displacement at that point due to the second wave in the absence of the first wave.

The resultant displacement (R) at that point when both the waves act simultaneously is

R = y₁± y₂

The ‘+’ sign is used when both displacements ...