When two progressive waves y1 = 4 sin (2x – 6t) and
y2 = 3 sin
are superimposed, the amplitude of the resultant wave is
A1 = 4
A2 = 3 A = 5
= –/2
When two waves superimpose, their displacements add up to give the resultant wave. The amplitude of the resultant wave depends on the phase difference between the two waves.
Given waves:
y1 = 4 sin(2x - 6t)
y2 = 3 sin
Step 1: Identify the amplitudes and phase difference
Amplitude of first wave, A1 = 4
Amplitude of second wave, A2 = 3
The phase difference (φ) between the two waves is the difference in their phase angles. The second wave has an additional phase of -π/2 compared to the first wave.
Therefore, phase difference φ = π/2 radians (the magnitude of the difference).
Step 2: Use the formula for the amplitude of the resultant wave
The amplitude A of the resultant wave when two waves of amplitudes A1 and A2 with a phase difference φ superimpose is given by:
Step 3: Substitute the values
A1 = 4, A2 = 3, φ = π/2
cos(π/2) = 0
Therefore, the equation simplifies to:
Final Answer: The amplitude of the resultant wave is 5 units.
Superposition Principle: When two or more waves travel through the same medium, the resultant displacement at any point is the algebraic sum of the displacements of the individual waves.
Interference: The phenomenon of superposition of waves, which results in a new wave pattern. It can be constructive (amplitude increases) or destructive (amplitude decreases).
Key Formula: The amplitude of the resultant wave from two interfering waves is given by , where φ is the phase difference.
Special Cases: