00:01
So in this question, we have two sinusoidal wave and they have the same amplitude.
00:05
Both of them have the amplitude of 9mm and they have the same worthness.
00:10
They're pretty much just like the same side wave, but with a different face.
00:17
So they are traveling together along the string and they are pictured onto this figure.
00:25
And figure 1638 is a figure on the book.
00:29
Now i have this valley called value a.
00:34
So it's when it travels in the negative direction of the x -axis by a distance of 50 cm in 8 milliseconds.
00:46
So that is telling us the speed of traveling.
00:50
So when value a is traveling like that, the tick marks along the axis are separated by 10 centimeters.
00:57
So every one of these is 10 centimeters.
00:59
So let's the equation for one wave be of the form of ym, sine kx plus or minus omega t plus 51, or 5 1 and 0.
01:17
And then for the equation for the other wave, what are the ym, k omega, phi, and the sign.
01:37
Okay, so firstly, it is apparent that they have the same amplitude.
01:46
So this amplitude of the second wave is also 9mm.
01:51
We can also look at k.
01:53
In order to do k, we have to read out the lambda because k equals 2 pi over lambda.
02:01
And each tick is 10 cm.
02:03
Here we have 1, 2, 3, 4.
02:08
Like this in a pyramid and that is 4 tick.
02:11
So that is 40 centimeters.
02:14
So we have 2 pi over 40 centimeter...