sound

In which medium sound can't travel?

• solid

• liquid

• gas

• vacuum

What is an echo

• deflected sound

• refracted sound

• reflected sound

• diffracted sound

In which medium speed of sound are fastest?

• vacuum

• solid

• liquid

• gas

What is the range of frequencies audible to the human ear

• lower than 20 Hz

• 20 Hz - 20.000 Hz

• higher than 20.000 Hz

• 0 Hz - infinite Hz

What is ultrasound?

• Sound with a frequency higher than 20.000 Hz

• Sound with a frequency lower than 20 Hz

• Sound with a frequency 20 Hz

• sound with a frequency 20.000 Hz

look at the picture. There are 4 sound wave with different amplitude and wavelength. Which sound wave has loudest sound?

• A

• B

• C

• D

look at the picture. There are 4 sound wave with different amplitude and wavelength. Which sound wave has highest pitch?

• A

• B

• C

• D

The delay time between light of thunder and sound of thunder is 2 seconds. If the speed of sound at the air is 340 m/s, how far the thunder from you?

• 680 m

• 170 m

• 342 m

• 338 m

A boat is using echo-sounding equipment to measure the depth of the water underneath.

The equipment in the boat sends a short pulse of sound downwards and detect the echo after a time interval 4 seconds. The speed of sound in water is 1500 m/s. Calculate the depth of water!

• 6000 m

• 5800 m

• 3000 m

• 2600 m

__________ means to move back and forth quickly.

• Pitch
• Amplitude
• Vibration
• Echo