00:01
In this problem, we have been given the two wave equations.
00:04
Y1 is equal to a sine kx minus omega -t plus phi, and the other equation of wave is a times sine kx plus omega -t.
00:16
And these two equations, they are combining to form a standing wave.
00:19
That's what we have been given.
00:21
And we have to show that the position of node that will be dependent on the initial value of this phase angle.
00:31
And also we need to show at end that the distance between two successive nodes, that's not going to depend on this file, it's still going to be lambda over 2.
00:40
So first, to get the idea of the formation of standing wave, we just combine these two waves, because that's what the superposition principle says.
00:49
So here, e comes as common, and we add sine kx plus omega -t with sine kx minus omega -t plus 5 and here we apply sign c plus sign d identity and this is equal to two sign c plus d over 2 times cost c minus d over 2 so let's consider kx plus omega t as c and kx minus omega t plus 5 as d and upon adding them we're going to get the value for y coming out to be 2a sine kx plus 5 by 2 times cost of omega t minus 5 by 2.
01:31
And when we talk about the position of node, in that case, the resultant displacement, that should be 0.
01:38
So when we equate y with 0, we're going to get sine kx plus 5 by 2, it's equal to 0...