Equation of a progressive wave is given by

y=0.2cosπ0.04t+.02xπ6

The distance is expressed in cm and time in second. What will be the minimum distance between two particles having the phase difference of π/2

(1) 4 cm

(2) 8 cm

(3) 25 cm

(4) 12.5 cm

(3) Comparing with y=acos(ωt+kxϕ),

We get k=2πλ=0.02πλ=100cm

Also, it is given that phase difference between particles Δϕ=π2.

Hence path difference between them Δ=λ2π×Δϕ=λ2π×π2=λ4=1004=25cm 

Difficulty Level:

  • 11%
  • 21%
  • 53%
  • 16%