What is the result when two waves meet in phase?

When two waves meet in phase, they align perfectly at their crests and troughs. This means that the positive displacements from the equilibrium position of one wave coincide with the positive displacements of the other wave. As a result, the individual amplitudes of the waves add together constructively.

This constructive interference leads to a resultant wave that has an increased amplitude compared to the individual waves. The amplitude is directly related to the energy carried by the waves, so when the amplitude increases, the energy of the resultant wave also increases. This phenomenon is fundamental in wave physics and is a key characteristic of wave behavior when two waves interact in this manner.

In contrast, the other outcomes like cancellation or reflection are associated with different types of interactions. Cancellation occurs when waves meet out of phase, while reflection pertains to a change in direction when waves encounter a barrier. Additionally, the speed of a wave is determined by the medium through which it travels, not directly by the interaction of two waves.