Waves

Question 1

How can waves be described?

Answer 1

Waves can be described as
oscillations
, or
vibrations
, about a rest position

Question 2

What is an oscillation?

Answer 2

Vibration

Question 3

What do sound waves do to particles?

Answer 3

sound waves cause air particles to vibrate back and forth

Question 4

What do ripples in the water do to particles?

Answer 4

ripples cause water particles to vibrate up and down

Question 5

Does the direction of oscillations vary?why?

Answer 5

The direction of these oscillations is the difference between longitudinal or transverse waves.

Question 6

Describe the oscillations in longitudinal waves…

Answer 6

In
longitudinal waves
, the vibrations are parallel to the direction of wave travel

Question 7

What are longitudinal waves?

Answer 7

A wave that moves in the same direction as the direction in which the particles are vibrating.

Question 8

Describe oscillations in transverse waves….

Answer 8

In
tranverse waves
, the vibrations are at right angles to the direction of wave travel.

Question 9

What is a transverse wave?

Answer 9

A wave that moves in a direction at right angles to the way in which the particles are vibrating.

Question 10

What do mechanical waves do to to oscillations?

Answer 10

They cause oscillations of particles in a solid, liquid or gas and must have a medium
to travel through. Once the wave has passed, the medium ends up back in its rest position.

Question 11

What is a medium?

Answer 11

A material through which a wave can be transmitted (propagate).

Question 12

Are mechanical waves transverse or longitudinal?

Answer 12

Mechanical waves can be longitudinal or transverse.

Question 13

Describe the oscillations in electromagnetic waves…..

Answer 13

Electromagnetic waves cause oscillations in electrical and magnetic fields. All electromagnetic waves are transverse

Question 14

What do all waves transfer?

Answer 14

All waves transfer energy but they do not transfer
matter
.

Question 15

What is matter?

Answer 15

Sub-atomic particles and anything made from them, such as atoms and molecules, are matter. Energy and forces are not matter.

Question 16

What are the key parts of a wave?

Answer 16

Rest position
Displacement
Park
Trough
Amplitude
Wavelength
Time period
Frequency

Question 17

What is the rest position of a wave?

Answer 17

the undisturbed position of particles or fields when they are not vibrating.

Question 18

What is the displacement of a wave?

Answer 18

the distance that a certain point in the medium has moved from its rest position.

Question 19

What is the peak of a wave?

Answer 19

the highest point above the rest position

Question 20

What is the trough of a wave?

Answer 20

the lowest point below the rest position

Question 21

What is the amplitude of a wave?

Answer 21

the maximum displacement of a point of a wave from its rest position.

Question 22

What is the wavelength of a wave?

Answer 22

distance covered by a full cycle of the wave. Usually measured from peak to peak, or trough to trough

Question 23

What is the time period of a wave?

Answer 23

the time taken for a full cycle of the wave. Usually measured from peak to peak, or trough to trough

Question 24

What is the frequency of a wave?

Answer 24

the number of waves passing a point each second.

Question 25

Describe the vibrations in a longitudinal wave….

Answer 25

In longitudinal waves , the vibrations are parallel to the direction of wave travel.

Question 26

Name 3 examples of a longitudinal wave…

Answer 26

sound waves ultrasound waves seismic P-waves

Question 27

What do longitudinal wave show areas of?

Answer 27

Longitudinal waves show areas of compression and rarefaction :

Question 28

What is a compression?

Answer 28

An area of increased pressure. In longitudinal waves, the particles in areas of compression are closer together than on average.

Question 29

What is rarefaction?

Answer 29

An area of reduced pressure. In longitudinal waves, the particles in areas of rarefaction are further apart than on average.

Question 30

Describe the vibrations in transverse waves….

Answer 30

In tranverse waves , the vibrations are at right angles to the direction of wave travel.

Question 31

What is a transverse wave?

Answer 31

A wave that moves in a direction at right angles to the way in which the particles are vibrating.

Question 32

Name 5 examples of a transverse wave….

Answer 32

ripples on the surface of water vibrations in a guitar string a Mexican wave in a sports stadium electromagnetic waves – eg light waves, microwaves, radio waves seismic S-waves

Question 33

How are transverse waves often demonstrated?

Answer 33

Transverse waves are often demonstrated by moving a rope rapidly up and down.

Question 34

What is air made from?

Answer 34

Many tiny particles

Question 35

What happens to the tiny particles in air when sound is created?

Answer 35

The air particles vibrate and collide with each other causing vibrations to pass between air particles

Question 36

How these tiny particles help is hear sound?

Answer 36

They vibrate through a persons ear and vibrate their eardrum

Question 37

What does light travel faster than?

Answer 37

Light travels much faster than sound and air

Question 38

What types of waves are sound waves?

Answer 38

Longitudinal waves

Question 39

What do longitudinal waves do to the tiny particles (sound)?

Answer 39

They cause the particles to vibrate parallel to the direction of wave travel

Question 40

What can the vibrations caused by longitudinal waves do?

Answer 40

The vibrations can travel through solids, liquids or gases

Question 41

What does the speed of sound depend on?

Answer 41

The medium through which it is travelling

Question 42

What is the medium?

Answer 42

A material through which a wave can be transmitted (propagate).

Question 43

What is the speed of sound when travelling through air?

Answer 43

About 330 metres per second (m/s)

Question 44

What can sound not travel through?

Answer 44

A vacuum

Question 45

What is a vacuum?

Answer 45

A volume that contains no matter

Question 46

Why can sound not travel through a vacuum?

Answer 46

Because there are no particles to carry the vibrations

Question 47

What may change when waves are transmitted at an interface (boundary)

Answer 47

It may change its direction

Question 48

What is refraction?

Answer 48

Process by which a wave changes speed and sometimes direction upon entering a denser or less dense medium

Question 49

What can all waves be?

Answer 49

Refracted

Question 50

What is a ray diagram?

Answer 50

Diagram that represents the direction and angle of travel of light.

Question 51

The density of a material is one of the factors that affects….. (refraction)

Answer 51

the speed that a wave will be transmitted through it.

Question 52

What does the word “FAST” mean in terms of refraction?

Answer 52

F:aster A:way S:lower T:owards

Question 53

What are the 3 things that can happen to Waves arriving at the interface (boundary) between two materials?

Answer 53

They can either be Reflected Transmitted Or absorbed

Question 54

What happens to a wave when it is absorbed?

Answer 54

Energy is 'taken-in' by the material and the internal energy of the material will increase

Question 55

What 3 factors will determine what happens to most of the wave energy?

Answer 55

The type of wave, its properties such as wavelength, and the difference between the two media

Question 56

What has a big effect on how much of the wave’s energy is reflected, absorbed or transmitted at an interface?

Answer 56

Wavelength