Chapter 9 Waves Flashcards Preview

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Flashcards in Chapter 9 Waves Deck (49):
1

Wave

transmitter of energy without the movement of particles from place to place. The vibration of particles or energy fields is involved.

2

Transverse Wave

wave involving the vibration of particles perpendicular to the direction of energy transfer

3

Compression Wave / Longitudial Waves

wave involving the vibration of particles in the same direction as energy transfer

4

Medium

material through which a wave moves

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Vibrations

repeated fast back-and-forth movements

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Compression

region in which the particles are closer than when not disturbed by a wave

7

Rarefaction

region in which the particles are further apart than when not disturbed by a wave

8

Frequency

number of vibrations in one second, or the number of wavelengths passing in one second

9

Hertz

unit of frequency; its abbreviation is Hz. One hertz is equal to one vibration every second.

10

pITCH

Highness or lowness of a sound. The pitch that you hear depends on the frequency of the vibrating air.

11

Wavelength

distance between two neighbouring crests or troughs of a wave. This is the distance between two particles vibrating in step.

12

Amplitude

maximum distance that a particle moves away from its undisturbed position

13

Sonar

use of reflected sound waves to locate objects under water (sound navigation and ranging)

14

Echolocation

Use of sound to locate objects by detecting echoes

15

Ultrasound

sound with frequencies too high for humans to hear

16

Ear Canal

the tube that leads from the outside of the ear to the eardrum

17

Eardrum

a thin piece of stretched skin inside the ear that vibrates when sound waves reach it

18

Membrane

a thin layer of tissue

19

Auricle

the fleshy outside part of the ear

20

Cochlea

the snail-shaped part of the inner ear. It is lined with tiny hairs that are vibrated by sound and stimulate the hearing receptors.

21

Semicircular Canals

three curved tubes, filled with fluid, in the inner ear that control your sense of balance

22

Auditory Nerve

a large nerve that sends signals to the brain from the hearing receptors in the cochlea

23

Ossicles

a set of three tiny bones that send vibrations from the eardrum to the inner ear. They also make the vibrations larger.

24

Oval Window

an egg-shaped hole covered with a thin tissue. It is the entrance from the middle ear to the outer ear.

25

Relative Intensity

a measure of how loud a sound is using a sound meter

26

Sound Level

the energy of sound that is an indication of the loudness of a sound

27

Decible

a unit of measurement of relative sound intensity

28

Threshold of Hearing

the lowest level of sound that can be heard by the human ear

29

Threshold of Pain

the lowest level of sound that causes pain to the human ear

30

Electromagnetic Spectrum

complete range of wavelengths of energy radiated as electric and magnetic fields

31

Radio Waves

low energy electromagnetic waves with a much lower frequency and longer wavelength than visible light

32

Infa-Red Radiation

nvisible radiation emitted by all warm objects. You feel infra-red radiation as heat.

33

Visible Light

very small part of the electromagnetic spectrum to which our eyes are sensitive

34

Ultraviolet Radiation

invisible radiation similar to light but with a slightly higher frequency and more energy

35

Xray

high-energy electromagnetic waves that can be transmitted through solids and provide information about their structure

36

Gamma Rays

high-energy electromagnetic radiation produced during nuclear reactions. They have no mass and travel at the speed of light.

37

Electromagnetic Waves

electromagnetic energy that is transmitted as moving electric and magnetic fields. There are many different types of electromagnetic energy, e.g. light, microwaves, radio waves.

38

Ray

narrow beams of light

39

Beam

wide stream of light rays, all moving in the same direction

40

Reflection

bouncing off the surface of a substance

41

Luminous

releasing its own light

42

Scattering

describes light sent in many directions by small particles within a substance

43

Transparent

describes a substance that allows most light to pass through it. Objects can be seen clearly through transparent substances.

44

Translucent

allowing light to come through imperfectly, as in frosted glass

45

Opaque

describes a substance that does not allow any light to pass through it

46

Lateral Inversion

reversed sideways

47

Refraction

change in the speed of light as it passes from one substance into another. It usually involves a change in direction.

48

Normal

a line drawn perpendicular to a surface at the point where a light ray meets it

49

Photons

a particle such as a quantum of light or electromagnetism