Ultrasound and Infrasound

Question 1

Between what frequency of sound can humans hear?

Answer 1

20Hz- 20,000Hz

Question 2

Define ultrasound and what is it used for?

Answer 2

Ultrasound is sound with frequencies above 20,000. Some animals, such as dolphins, use it for communication. It is also used in foetal scanning as the different body tissues reflect ultrasound by differing amounts and the echoes are used to create and image

Question 3

Define infrasound and what is it used for?

Answer 3

Infrasound is sound with frequencies beloq 20Hz. Some animals, such as wales, use it for communication

Question 4

What is the relationship between the closeness of particles and the speed sound travels?

Answer 4

The closer the particles, the faster the sound travels

Question 5

What is sonar?

Answer 5

Sonar is a technique used by ships to determine the depth of water. Pulses of ultrasound are reflected off the bottom of the seabed and the time delay is used to calculate the distance travelled.

Question 6

How is infrasound naturally produced?

Answer 6

• volcanoes
• avalanches
• ocean waves
• hurricanes
• earthquakes
• meteorite explosions
• animal movements

Question 7

What do humans use infrasound for?

Answer 7

to detect and monitor animal movement in remote locations, volcanic activity and meteorites

Question 8

What is the calculation used to measure the depth of the water?

Answer 8

distance travelled = speed of ultrasound x time delay

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