The maximum particle velocity in a wave motion is half the wave velocity. Then the amplitude of the wave is equal to

Options

(a) λ/4π
(b) 2λ/π
(c) λ/2π
(d) λ

Correct Answer:

λ/4π

Explanation:

For a wave, y = a sin [(2πvt/λ) – (2πx/λ)]
Here v = velocity of wave
.·. y = a sin [(2πvt/λ) – (2πx/λ)]
dy/dt = a (2πv/λ) cos [(2πvt/λ) – (2πx/λ)]
velocity = (2πav/λ) cos [(2πvt/λ) – (2πx/λ)]
Maximum velocity is obtained when
cos [(2πvt/λ) – (2πx/λ)] = 1
.·. v = (2πav/λ)
Then, v = v/2
(2πav/λ) = v/2 or a = λ/4π.