Answer:
Wave B has the longest wavelength
Explanation:
The wavelength of a wave is the distance between two consecutive points that are in phase.
The wavelength of a wave is also defined as the distance between successive crests or troughs along the z-axis.
A crest is the point of maximum upward displacement whereas a trough is a point of maximum downward displacement.
Comparing the three waves A, B and C over a unit distance.
Wave A:
Wave A has three crests and two troughs. The wave begins and ends at the rest position. There are 2½ successive points in phase in wave A
Therefore, the wavelength = 1/2.5 = 0.4
Wave B:
Over a unit distance, wave B has two crests and one trough. The wave begins at the rest position and ends at the top of a crest. There are 1¼ successive points in phase in wave B
Therefore, the wavelength = 1/1¼ = 0.8
Wave C:
Over a unit distance, wave C has four crests and four troughs. The wave begins and ends at the rest position.
There are 4 successive points in phase in wave B
Therefore, the wavelength = 1/4 = 0.25
Therefore, wave B has longest wavelength
