A wave equation which gives the displacement along the `Y` direction is given by the equation `y=10^4sin(60t+2x)`, where x and y are in metres and t is time in seconds. This represents a wave

Options

A. of amplitude `10^(-4)m` travelling in the negative x direction
B. of wavelength `pi` metre
C. of frequency `(30)/(pi)` hertz
D. travelling with a velocity of 30 m/s, in the positive x direction

Answer

D

Explanation

`y = 10^(-4) sin[60t + 2x]`
`= 10^(-4) sin 2pi [(30t)/(pi) + (x)/(pi)]`
Comparing with the standard equation, we get
`A = 10^(-4), T = (pi)/(30) :. n = (30)/(pi), lamda = pi`
`:. v = n lamda = (30)/(pi) xx pi = 30 m//s`
Wrong statement. Wave is travelling in the positive x direction