00:01
In this question, we have ultrasonic waves being used to detect tumor inside the liver.
00:08
So this is the diagram.
00:10
So the arrows represent how the ray travels.
00:14
Okay, we are given that the speed of ultrasound in liver is 90 % of the speed of ultrasound in the surrounding medium.
00:41
So this is the top layer, it's the surrounding medium.
00:52
Okay, so we want to find the depth of the tumor.
00:56
And the depth of the tumor, i'm going to call it d.
01:02
So to solve this question, first we are going to find the angle of reflection.
01:11
So the refractive index of liver, of the ultrasound of liver, for ultrasound is equal to c over v so which is c devoured by 0 .9c so we get 1 .11 and then using snell's law okay n1 sine data 1 equals to n2 side data 2 okay and then um so n1 is some arbitrary number n2 will just be 1 .11 of n1 right so we have sine 50 degrees equals to 1 .11, side data 2.
02:09
So data 2 is xx of sine 50 degrees divided by 1 .11...