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

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 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 sine waves travel in the same direction in a medium. The amplitude of each wave is A and the phase difference between the two waves is 120°. The resultant amplitude will be

The fundamental frequency of a string is proportional to