Ultrasound

Question 1

what is ultrasound?

Answer 1

sound with frequencies higher than 20000 Hz

Question 2

what happens at wave boundaries?

Answer 2

some is transmitted and refracted (partially reflected)

Question 3

how is ultrasound used?

Answer 3

• medical imaging (pre-natal scanning of a foetus)

- industrial imaging (finding flaws in materials)

Question 4

how does medical imaging work?

Answer 4

• reaches a boundary between two different media and some of the wave is reflected back and detected
• exact timing and distribution of echoes are processed by a computer

Question 5

how does finding flaws in materials work?

Answer 5

• in pipes or materials such as wood or metal
• ultrasound reflected by far side of material
• if there are flaws, waves will be reflected sooner