Ultrasound, Infrasound and Seismic Waves

Question 1

What is ultrasound?

Answer 1

Sound with frequencies higher than 20,000Hz.

Question 2

What is partial reflection?

Answer 2

When some of the wave, going from one medium into another, is reflected off the boundary and some is transmitted/refracted.

Question 3

How can a flaw in a material be detected using ultrasound?

Answer 3

Ultrasound entering will usually be reflected by the far side, but if there is a flaw, the wave will be reflected sooner.

Question 4

What in boats is ultrasound also used in?

Answer 4

Echo sounding

Question 5

How do boats use ultrasound?

Answer 5

It is used to find out the distance to the seabed or to locate objects in deep water?

Question 6

What is infrasound?

Answer 6

Sound with frequencies lower than 20Hz.

Question 7

What type of wave is produced when there’s an earthquake?

Answer 7

Seismic waves at a range of frequencies.

Question 8

What happens if seismic waves are refracted?

Answer 8

They change speed gradually.

Question 9

What can P-waves travel through in the earth that S-waves cannot?

Answer 9

The earth’s core

Question 10

Which waves are faster, P or S?

Answer 10

P-waves

Question 11

Which wave, out of P and S, are longitudinal and transverse?

Answer 11

P- waves are longitudinal and S-waves are transverse.

Question 12

What can P-waves travel through?

Answer 12

Solids and liquids

Question 13

What can S-waves travel through?

Answer 13

Only solids