Two wave pulses travel in opposite directions on a string and approach each other. The shape of one pulse is inverted with respect to the other.

Two wires A and B, having identical geometrical construction, are stretched from their natural length by small by equal amount. The young modulus of the wires are Y_A and Y �_B whereas the densities are ρ_A and ρ_B. It is given that Y_A > Y_B and ρ_A > ρ_B. A transverse signal started at one end takes a time t₁ to reach the other end for A and t₂ for B.

Consider two waves passing through the same string. Principle of superposition for displacement says that the net displacements of a particle on the string is sum of the displacements produced by the two waves individually. Suppose we state similar principles for the net velocity of the particle and the net kinetic energy of the particle. Such a principle will be valid for

Two periodic waves of amplitudes A₁ and A₂ pass through a region. If A₁ > A₂, the difference in the maximum and minimum resultant amplitude possible is

Two waves of equal amplitude A, and equal frequency travel in the same direction in a medium. The amplitude of the resultant wave is