Answer:
B. Two waves have displaced in opposite directions
Step-by-step explanation:
Interference occurs when two waves meet at a point in space. When this occurs, two extreme conditions can occur:
- if the two waves are in phase (=displacement in the same direction), the amplitude of the resultant wave is equal to the sum of the amplitudes of the two waves:
A = A1 + A2
and this condition is called constructive interference
- if the two waves are in anti-phase (=displacement in opposite directions), the amplitude of the resultant wave is equal to the difference of the amplitudes of the two waves:
A = |A1 - A2|
and this condition is called destructive interference. Note that if A1=A2, the amplitude of the resultant wave is zero.