Waves at an Interface

Question 1

Waves can either be ___ or ___ at in interface

Answer 1

Reflected

Transmitted

Question 2

How is sonar used to build up a picture?

Answer 2

Short pulses of sound are emitted
Time taken for sound to travel to an interface and back recorded
Determines the position of objects

Question 3

Example of sonar use

Answer 3

Boats and submarines

Question 4

How is ultrasound used to build up a picture?

Answer 4

Gel used to transmit sound (in pulses) from transducer through the outer body without reflection
Waves reflected back from each layer of tissue

Question 5

Why are the wavelengths used for sonar and ultrasound very different?

Answer 5

Because they are getting objects of very different sizes

Question 6

Why does the wavelength need to be smaller to detect small objects?

Answer 6

So that a higher resolution image can be formed

resolution depends on wavelength

Question 7

What does pulse duration affect?

Answer 7

The range over which waves can travel and return

Question 8

What does increasing the pulse duration do?

Answer 8

Increases the range

Reduces the amount of information that can be gathered