Waves and EM spectrum YEAR 9

Question 1

Define transverse wave

Answer 1

Oscillations are perpendicular to direction of energy transfer

Question 2

Define longitudinal wave

Answer 2

Oscillations are parallel to direction of energy transfer

Question 3

Give 2 examples of transverse waves

Answer 3

Light
Ripples on water

Question 4

Time period

Answer 4

Time for one oscillation to pass a point

Question 5

Compression in longitudinal waves

Answer 5

regions of high pressure due to particles being close together

Question 6

Rarefaction in longitudinal waves

Answer 6

rarefactions are regions of low pressure due to particles being spread further apart.

Question 7

Speed of sound in air

Answer 7

330 m/s

Question 8

Humans can hear from

Answer 8

20 to 20000Hz

Question 9

Uses of ultrasound

Answer 9

Pregnancy scans
Dog whistles
Cleaning jewellery

Question 10

What is the epicentre

Answer 10

The point on the earth surface directly above the origin of an earthquake

Question 11

What are p waves

Answer 11

Primary waves
Longitudinal
Travel through solids and liquids

Question 12

What are S waves

Answer 12

Secondary waves
Transverse
Only travel through solids

Question 13

are p or s waves faster

Answer 13

p waves are faster

Question 14

How are p and s waves used

Answer 14

To determine the structure of Earth.
To detect earthquakes

Question 15

How is ultrasound used for pregnancy scans

Answer 15

Ultrasound gel applied to woman’s belly, ensuring contact to the ultrasound probe
Ultrasound probe is used to produce a scan of the womb by emitting ultrasound waves which are registered when they reflect off the baby

Question 16

Waves Transmit definition

Answer 16

When a wave is emitted

Question 17

Waves Absorb definition

Answer 17

When a surface takes in a wave without it being reflected

Question 18

incident wave definition

Answer 18

The incident wave is the one that approaches the boundary

Question 19

EM wave with highest wavelength

Answer 19

Radio waves

Question 20

EM wave with highest frequency

Answer 20

Gamma rays

Question 21

Uses of gamma rays

Answer 21

Cancer treatment
Observing space

Question 22

Why are ultrasound rays used for imaging pregnancy scans

Answer 22

They are partially reflected at the boundary between surfaces

Question 23

Are EM waves longitudinal or transverse

Answer 23

transverse

Question 24

How do does ionising radiation hurt us

Answer 24

Ionising radiation knocks out electrons from atoms
High doses kill living cells
Low doses cause gene mutation and cancer