Waves And Radiation

Question 1

What is sound ?

Answer 1

Sound is a form of energy

Question 2

What is sound caused by ?

Answer 2

All sounds are caused by vibrating objects

Question 3

Which type of wave is a sound wave ?

Answer 3

Longitudinal wave

Question 4

What can sounds travel through ?

Answer 4

Solids, liquids and gases but not a vacuum (since it has no particles)

Question 5

What is the speed of sound ?

Answer 5

340m/s

Question 6

What is frequency ?

Answer 6

The frequency of a sound is the number of vibrations in a second measured in hertz (Hz)

Question 7

Low frequency

Answer 7

Low pitch

Question 8

High frequency

Answer 8

High pitch

Question 9

What is amplitude ?

Answer 9

Amplitude is the distance from the centre of the wave to the top of a crest measured in metres

Question 10

The larger the amplitude…

Answer 10

The louder the sound

Question 11

What is wavelength?

Answer 11

Wavelength is from the top of one wave to the top of the next wave measured in metres.

Question 12

What is the normal hearing range from humans ?

Answer 12

20 - 20000 Hz

Question 13

What is ultrasound ?

Answer 13

Ultrasound is a sound with a frequency above human hearing.

Question 14

What is the loudness of a sound measured in ?

Answer 14

The loudness of a sound is measured in decibels (dB)

Question 15

Sound levels over _____ can damage hearing

Answer 15

80 dB

Question 16

What is noise pollution ?

Answer 16

Noise pollution is any annoying and potentially harmful environmental noise

Question 17

Radio waves

Answer 17

Radio waves are the lowest frequencies in the electromagnetic spectrum and are used mainly for communications e.g. TV and radio

Question 18

Microwaves

Answer 18

Microwaves are basically extremely high frequency radio waves

Question 19

What are microwaves used for ?

Answer 19

We can use microwaves to cook many types of food, mobile phones use microwaves and they are also used by fixed traffic speed cameras and for radar which is used by aircraft, ships and weather forecasters

Question 20

Infrared

Answer 20

Infrared waves carry heat. They are given off by hot objects and you can feel the on your skin

Question 21

Infrared radiation applications

Answer 21

Remote controls, heat lamps, short range communications, thermal imaging cameras, thermal imaging in medicine

Question 22

Visible light dangers

Answer 22

Laser light can be very intense. Some lasers can even cut through metal.

Question 23

Ultraviolet applications

Answer 23

Detecting forged bank notes, setting nail varnish, treating vitamin D deficiency, treating some skin disorders

Question 24

Ultraviolet dangers

Answer 24

Ultraviolet can cause skin cancer

Question 25

X-rays

Answer 25

X-rays are used by doctors to see inside people. They pass easily through soft tissues but not so easily through bones

Question 26

Gamma rays

Answer 26

Gamma rays damage and kill living cells so they are used in medicine to kill cancer cells without having to resort to invasive surgery. This is called ‘radiotherapy’

Question 27

Longitudinal wave

Answer 27

A wave which the vibrations are in the same direction as the wave travels

Question 28

Transverse wave

Answer 28

A wave which rib rations are at right angles to the direction of the wave