waves for detection and exploration

Question 1

Why are sound waves mechanical?

Answer 1

they need a substance to travel through

Question 2

Why is there a limit to the range of human hearing?

Answer 2

conversion of sound waves in air to vibrations in ear (solid) only works over a limited range of frequencies

Question 3

What is the frequency range of normal human hearing?

Answer 3

20 Hz to 20 000 Hz

Question 4

What are ultrasound waves?

Answer 4

sound waves with a frequency above 20000 Hz

Question 5

What happens to ultrasound waves when they meet a boundary between two substances?

Answer 5

they are partially reflected and some are transmitted

Question 6

What is echo sounding used for?

Answer 6

detecting objects in deep water, measuring the depth of water

Question 7

What are the properties of P- waves

Answer 7

longitudinal, travel through liquids and solids

Question 8

What are the properties of S - waves

Answer 8

transverse, cannot travel through liquids

Question 9

which observation suggests that the outer core of the Earth must be liquid

Answer 9

S Waves are not detected on the other side of the earth