Question

(i) For the wave on a string described in Exercise 15.11, do all the points on the string oscillate with the same
(a) frequency,
(b) phase,
(c) amplitude? Explain your answers.
(ii) What is the amplitude of a point 0.375 m away from one end?

Answer 1

Concept :- in case of stationary wave , amplitude of wave varies .

(1) all the nodes except the nodes on the string have the same frequency and phase but not the same amplitude as you know, nodes are the points which do not vibrate at all .

(2) y = 0.06sin(2πx/3)cos(120πt)
Amplitude for the point at x = 0.375 is maximum value of |Y(0, 0.375)|
This is possible cos(120π×0) = 1

A = 0.06sin(2π × 0.375/3)
= 0.06sin(π/4)
= 0.06 × 1/√2
= 0.042 m