Science: Waves

Question 1

Any wave transfers XXXX from one place to another

Answer 1

ENERGY

Question 2

Sound waves cause particles to vibrate backwards and forwards in the direction of the wave, this produces areas of high pressure (called XXXXXX) and low pressure (called XXXXXX)

Answer 2

areas of high pressure (compression) and low pressure (rarefaction)

Question 3

As there are areas where the air pressure is different in a sound wave, we can call sound waves a type of XXXXX wave

Answer 3

PRESSURE

Question 4

What can sound be detected and produced with?

Answer 4

Sound can be detected with a microphone, the microphone will change air pressure into a changing potential difference

Sound can be produced with a loudspeaker, the changing potential difference causes changes in air pressure

Question 5

What are transverse waves?

Answer 5

Transverse waves vibrate at 90o to the direction at which they are travelling, they move up and down as well as forward

Question 6

What are Longitudinal waves?

Answer 6

Longitudinal waves vibrate in the direction in which they are travelling

Question 7

What happens when waves are out together?

Answer 7

When waves are put together they superpose, this means
they will either add together or cancel each other out

Question 8

What happens when waves are in line with each other?

Answer 8

When the waves are in line with one another they add together, increasing the amplitude of the wave

Question 9

What happens when waves are NOT in line?

Answer 9

When the waves are not in line, they will cancel each other out, decreasing the amplitude of the wave

Question 10

What sound frequencies can humans hear?

Answer 10

Humans can hear sounds with a frequency between 20–20000Hz.

Question 11

What is ultrasound?

Answer 11

ultrasound is any sound with a frequency of higher than
20 000 Hz

Question 12

What can ultrasound be used for?

Answer 12

• Ultrasonic cleaning – dirt particles are ‘shaken’ off of objects
• Physiotherapy – the ultrasound waves causes liquid particles in the body to move more quickly and hence get warmer

Question 13

Examples of items on the electromagnetic spectrum - from low energy/frequency to high energy/frequency? (And decreasing in wavelength)
+ examples of uses for each type

Answer 13

Radio waves (TV signals)
Micro waves (mobile phone signals)
Infrared (heating and cooking)
Visible light (photography)
Ultraviolet light (detecting forgeries)
X rays (imaging broken bones)
Gamma rays (killing cancer cells)

Question 14

What is IONISATION?

Answer 14

High energy waves can lead to ionisation, where electrons are knocked off of atoms in cells

This can cause mutations in cells if the DNA is affected and this can lead to cancerous tumours forming