Explanation:
The scanner records the time from when a ultrasound wave is emitted to when its reflection is received. A technician calculates the depth of the reflection using the equation as :
[tex]\text{depth}=\dfrac{1}{2}\times \text{speed of ultrasound in patient}\times \text{time recorded by scanner}[/tex]
The distance covered by ultrasonic wave when it was emitted and gets reflected is 2d. Speed is given by :
[tex]v=\dfrac{d}{t}[/tex]
d is distance and t is time
Here, d = 2d
So, the factor of (1/2) is used because the distance covered by the wave is 2 times when it was emitted and received.
