Echoes and ultrasound

Above what frequency is ultrasound?

• 10,000 Hz

• 20 Hz

• 20,000 seconds

• 20,000 Hz

Tags

NGSS.HS-PS4-1

Which of these is a use of ultrasound?

• Taking photos of unborn babies

• Taking photos of jewellery

• Cleaning babies

Tags

NGSS.HS-PS4-5

What's the missing word?

Sound waves can ________ off surfaces. We hear sound reflections as echoes. Hard, smooth surfaces are particularly good at reflecting sound. This is why empty rooms produce lots of echoes.

• Reflect

• Absorb

• Ping

• Slide

Tags

NGSS.MS-PS4-2

Which refers to a method that relies on sound waves and is used by different animal species for navigation, communication, and finding food?

• Analog signalling

• Infrared detection

• Digital location

• Echolocation

What happens when the sound waves released by a bat hit an object?

• The sound waves are diffused

• The sound waves are refracted

• The sound waves are absorbed

• The sound waves are reflected

Tags

NGSS.MS-PS4-2

Which statement best describes echolocation in dolphins?

• Echolocation helps dolphins find food only

• Echolocation helps dolphins avoid predators only

• Echolocation helps dolphins avoid predators and find food

• Dolphins don't use echolocation

In which of these places would you not hear an echo?

• Cave

• Tunnel

• Field

• A closed hall

SONAR is a technique or device that's used for:

a. detecting objects under water

b. detect cracks in metal structures

c. measure depth of the sea

d. investigate the abdomen and heart conditions

• A and B

• B and C

• A and C

• A and D

Tags

NGSS.MS-PS4-2