Question Detail
Question
The text states that for a wave propagating in the positive x-direction, the wave equation can be written as y = Asin(kx - ωt), where kx - ωt is the phase. If a wave is described by y = Asin(kx + ωt), which direction is it propagating?
Correct Answer
Option B is the correct answer.
Detailed Explanation
According to the document (page 2), for a wave propagating in the positive x-direction, the phase term is (kx - ωt). The document also states that for a wave traveling to the left (negative x-direction), a similar analysis will show that the velocity is negative. A phase of (kx + ωt) implies that as time t increases, x must decrease to keep the phase constant, thus indicating propagation in the negative x-direction.
Hint
Refer to the section on 'Wave Motion' and the explanation of phase velocity on page 2, particularly the note about positive and negative velocity based on the phase argument.