Question

The scanner records the time from when a ultrasound wave is emitted to when its reflection is received

Answer 1

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 :

$\text{depth}=\dfrac{1}{2}\times \text{speed of ultrasound in patient}\times \text{time recorded by scanner}$

The distance covered by ultrasonic wave when it was emitted and gets reflected is 2d. Speed is given by :

$v=\dfrac{d}{t}$

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.