A standing wave is formed by the interference of two travelling waves, each of which has an amplitude `A = pi cm` , angular wave number `k= (pi//2)` per centimetre.
(a) Calculate the distance between two successive antinodes.
(b) What is the amplitude of the standing wave at `x=0.50 cm` from a node?

Answer

A, B, C

Explanation

(a) Distance between successive antinodes
`=lambda/2 = pi/k = (pi/(p//2)) = 2cm `
(b) `A_(max) = 2A = (2pi) cm `
If x= 0 is taken as node, we shall taken sin
equation for `A_x`
`:. A_x = A_(max) = sin kx`
`= 2pi cm sin kx`
Put `k = pi/2` and `x=0.5`.