Week 10

Question 1

Do you think reflection is an important process when sound waves produce an echo?

Answer 1

Yes

Question 2

Does increasing the frequency increase the amplitude of a sound wave transmitted through the piece of paper?

Answer 2

no

Question 3

An interface between air and some other substance, like tissue or water, strongly scatters ultrasound waves. Which of the following is NOT a consequence of this?

Answer 3

Images are sharper with higher ultrasound frequencies.

Question 4

If the angle theta is large, then diffraction is important. It the angle is small (close to zero), then diffraction is not important.)

Answer 4

Diffraction will be somewhat important

Question 5

In order to form a reflection interface for sound waves, what must be true of the materials on either side of the interface?

Answer 5

They must differ in their acoustic impedance

Question 6

The ___________ of the reflected pulse relative to that of the incident pulse gives information on the type of interface that produced the reflection. The _______________ gives information about the distance between the transducer and the reflecting interface.

Answer 6

amplitude; travel time between when a pulse leaves and when it returns to the transducer