Question

In the wave equation

y = `0.5sin  (2pi)/lambda(400t - x)m`

the velocity of the wave will be:

Options

• 200 m/s

• `200sqrt2` m/s

• 400 m/s

• `400sqrt2` m/s

Answer 1

400 m/s

Explanation:

Comparing the given y  = `0.5sin ((2pi)/lambda400t - (2pi)/lambdax)` with the standard equation.

`omega = (2pi)/lambda400` and k = `(2pi)/lambda`

∴ Velocity of the wave (v) = `omega/k`

= `(2pi)/lambda 400/((2pi)/lambda)`

= 400 m/s