Sound

Question 1

What type of wave is a sound wave?

Answer 1

Longitudinal — particles vibrate back and forth in the same direction the wave travels.

Question 2

Through which medium does sound travel fastest: air, water, or solid?

Answer 2

Solid — because particles are closest together, so vibrations pass faster.

Question 3

What is pitch?

Answer 3

How high or low a sound is, based on its frequency.

Question 4

What is loudness?

Answer 4

How loud or quiet a sound is, based on its amplitude (wave height).

Question 5

What is an echo?

Answer 5

A reflected sound wave that travels back to your ears after hitting a surface.

Question 6

Why are echoes quieter than the original sound?

Answer 6

Because energy is lost (absorbed or spread out) as the wave reflects.

Question 7

How do microphones work?

Answer 7

They have a diaphragm that vibrates when sound hits it, converting sound into an electrical signal.

Question 8

How do speakers work?

Answer 8

Electrical signals make the diaphragm vibrate, pushing air to create sound waves.

Question 9

What is ultrasound?

Answer 9

Sound with a frequency above 20,000 Hz — too high for humans to hear.

Question 10

How does ultrasound clean things like false teeth?

Answer 10

It vibrates water so fast it creates tiny bubbles that pop (cavitation), loosening dirt.

Question 11

Why is ultrasound useful in physiotherapy?

Answer 11

It sends sound waves into deep tissues to promote healing without needing to cut skin.

Question 12

Why can astronauts see each other in space but can’t hear each other without radios?

Answer 12

Space is a vacuum — no particles to carry sound. Light can still travel, but not sound.

Question 13

A microphone captures sound and sends it as an electrical signal. What must it be doing inside?

Answer 13

Vibrating something (like a diaphragm) and converting those vibrations into electricity.

Question 13

A sound wave travels through a wall. What does this tell you about the wall’s particles?

Answer 13

They’re close enough for vibrations to transfer — sound can travel through solids.

Question 14

A dentist’s drill makes a high-pitched sound. What does that tell you about the sound wave?

Answer 14

It has a high frequency and short wavelength.

Question 15

Angelo Lamaj claps his hands in a cave and hears an echo 2 seconds later. What does that tell you about the distance of the wall?

Answer 15

The sound wave had to travel there and back. You can estimate the distance using distance = speed x time.

Question 16

Someone plays music through a speaker underwater. Why does it sound clearer if your head is under the water?

Answer 16

Sound travels faster and clearer in water than in air because particles are closer.

Question 17

Why can’t sound waves travel through a vacuum?

Answer 17

There are no particles to vibrate — sound needs a medium.

Question 18

Why might a study of only 20 patients not prove that ultrasound physiotherapy works?

Answer 18

Too small a sample — not enough people to be reliable or fair.

Question 19

How is sound made?

Answer 19

By vibrations that travel through a medium (like air or water).

Question 20

Can sound travel through a vacuum?

Answer 20

No — sound needs a medium to travel through.

Question 21

How do we hear sound?

Answer 21

Vibrations from the air move the eardrum, which sends signals to the brain.

Question 22

Why do some sounds hurt your ears?

Answer 22

They have a very high amplitude (loudness) or frequency (pitch).

Question 23

What’s the approximate speed of sound in air?

Answer 23

Around 343 m/s