Question

If a wave travelling in positive x-direction with $A=0.2$ m, velocity $=360$ m/s and $λ=60$ m, then correct expression for the wave is:

• A. $y=0.2 \sin[2π(6t + \fracx60)]$
• B. $y=0.2 \sin[π(6t + \fracx60)]$
• C. $y=0.2 \sin[2π(6t - \fracx60)]$
• D. $y=0.2 \sin[π(6t - \fracx60)]$

Hint:

For wave travelling in +x direction: $y = A \sin(kx - ω t)$.

Answer 1

The Correct Option is C

Step 1: $f = v/λ = 360/60 = 6$ Hz, $k = 2π/λ = 2π/60$.

Step 2: Wave in +x direction: $y = A \sin(kx - ω t) = 0.2 \sin(2π x/60 - 12π t) = 0.2 \sin[2π(6t - x/60)]$.