Question

FIGURE Q17.8 is a snapshot graph of two plane waves passing

through a region of space. Each wave has a 2.0 mm amplitude

and the same wavelength. What is the net displacement of the

medium at points a, b, and c?

Short answer

The net displacement of the medium at points a, b, and c are 4 mm, 0, - 4 mm respectively.

Step-by-step solution

Given data

A snapshot graph of two plane waves labelled 1 and 2 are given here.

The amplitude of each wave is, 2.0 mm.

Calculation of displacement

Adding the contributions from wave 1 and wave 2, we get the displacement of waves at three different points a, b and c from the following table where $D_1$is the displacement of wave 1, $D_2$is the displacement of wave 2 and $D_{net}$is the total displacement of the medium as:

	$D_1$	$D_2$	$D_{net}$
Point a	2 mm	2 mm	4 mm
Point b	2 mm	- 2 mm	0
Point c	- 2 mm	- 2 mm	- 4 mm