Sound

Question 0

Sound needs a medium

Answer 0

We can put an alarm clock or buzzer inside a bell jar and connect it to a vacuum pump. As air is removed, the sound becomes fainter.
Conclusion: sound needs a medium in which to travel.

Question 1

Sound

Answer 1

Is a form of energy
Produced by vibrations
Can travel through a solid, a liquid or a gas
Cannot travel through a vacuum

Question 2

Speed of sound and air

Answer 2

Speed of sound in air is 340m/s
Light is 3x10to the power of 8m/s
This is why we see lightening before we hear the thunder even though they happen at the same time

Question 3

Echo

Answer 3

Reflection of sound

Question 4

Ultrasound

Answer 4

Sound above our level of hearing

Question 5

Ear protection

Answer 5

People are working in a job where sound is above 70db(decibels) they have to wear ear protection(bust street traffic)

Question 6

Permanent ear damage

Answer 6

Sounds above 115 db

Question 7

Energy conversions in hearing

Answer 7

The movement energy is converted to electrical energy and goes to the brain to be processed

Question 8

Loudness

Answer 8

Measured in decibels

A sound level meter is used to measure the loudness of sound