Hertswood Academy Gcse Physics P1 5 The Use Of Waves For Communication And Evidence For The Universe Expanding

Front 1

What do waves transfer? (1 mark)

Back 1

Energy

Front 2

What are the two different type of waves? (1 mark)

Back 2

Transverse and Longitudinal waves

Front 3

Give some examples of transverse wave. (1 mark)

Back 3

Light, electromagnetic waves, water wave

Front 4

Give some example of longitudinal wave. (1 mark)

Back 4

Sound, ultrasound, shockwaves

Front 5

Do all electromagnetic waves travel at same speed? (1 mark)

Back 5

Yes

Front 6

What speed to electromagnetic waves travel at? (1 mark)

Back 6

The speed of light (300,000,000m/s)

Front 7

What is the difference between transverse and longitudinal waves? (2 marks)

Back 7

Transverse waves: Vibrations are perpendicular (at 90 degrees) to the direction of travel
Longitudinal waves: Vibration is parallel (in line) with the direction of travel

Front 8

What are the two areas of longitudinal waves? (1 mark)

Back 8

Compression (where the particles are squashed together)
Rarefaction (where the particles are spaced apart)

Front 9

State 3 properties of waves? (1 mark)

Back 9

Reflection, refraction and diffraction

Front 10

Which waves can be used for communication? (4 marks)

Back 10

Radiowaves - TV and radio
Microwaves - mobile phone and satellite TV
Infrared - remote controls
Visible light – photography

Front 11

What is the wave speed equation? (1 mark)

Back 11

v = f x λ
v = wave speed
f = frequency
λ = Wavelength

Front 12

What is the unit of wave speed (v)? (1 mark)

Back 12

Metres per second (m/s)

Front 13

What is the unit of frequency (f)? (1 mark)

Back 13

Herts (Hz)

Front 14

What is the unit of wavelength (λ)? (1 mark)

Back 14

Metres (m)

Front 15

Define frequency. (2 mark)

Back 15

The number of complete waves made in one second. It is measured in Hertz.
1 Hz = one wave per second

Front 16

Define wavelength. (1 mark)

Back 16

The length of one complete wave

Front 17

Draw a wave diagram showing wavelength and amplitude. (1 mark)

Back 17

Front 18

Give the correct order of EM spectrum. (7 marks)

Back 18

Radio wave (Longest wavelength & lowest frequency)
Microwave
Infrared
Visible
Ultraviolet
X-Ray
Gamma (Shortest wavelength & Highest frequency)
Note: Pneumonic to remember the order
Remember my instruction visible under X-Ray Glasses

Front 19

What is the range of wavelength of EM waves? (1 mark)

Back 19

10(-15) metres to 10(4) metres

Front 20

What is the normal? (1 mark)

Back 20

The normal is a line perpendicular (at 90 degrees) to the reflecting surface at the point of incidence

Front 21

State the law of reflection. (1 mark)

Back 21

Angle of Incidence = Angle of Reflection

Front 22

What is the relationship between the angle of incidence and the angle of reflection? (2 marks)

Back 22

The angle of incidence equals the angle of reflection
As the angle of incidence increases the angle of reflection increases

Front 23

What is the difference between a real and a virtual image?

(2 marks)

Back 23

A real image is made when the rays of light from the same place on the object actually cross. Real image is formed on projector screen.
A virtual image is made when the rays of light are diverging, so only appear to come from one place. Virtual image is formed in mirrors

Front 24

State the characteristics of the image made by a plane mirror.

(1 mark)

Back 24

Upright, same size as object, same distance from mirror as object, laterally inverted, virtual

Front 25

What is an echo? (1 mark)

Back 25

An echo is the reflection of sound waves that can be heard

Front 26

What is the definition of refraction? (1 mark)

Back 26

The change of direction of a wave when it crosses a boundary from one medium to another. Speed of wave changes

Front 27

What is the relationship between the angle of incidence and the angle of refraction? (2 marks)

Back 27

The angle of refraction is smaller than the angle of incidence
As the angle of incidence increases the angle of refraction increases

Front 28

What is the definition of diffraction? (1 mark)

Back 28

The spreading of waves when they pass through a gap or near an edge of an obstacle

Front 29

What determines the amount of diffraction of a wave? (1 mark)

Back 29

Significant diffraction only occurs when the wavelength of the wave is similar in size to the gap or obstacle

Front 30

What factor determines the pitch of sound? (1 mark)

Back 30

The frequency of wave
High frequency = High pitch
Low frequency = Low pitch

Front 31

What factor determines the loudness of sound? (1 mark)

Back 31

The amplitude of wave
Large amplitude = Loud sound
Small amplitude = Quiet sound

Front 32

What is an echo? (1 mark)

Back 32

Echo is a reflected sound of the wall

Front 33

Describe what the Doppler Effect is. (2 marks)

Back 33

If the sound source moves away from the observer, the waves stretch out to a longer wavelength, the frequency decreases and a low pith sound is heard
If the sound moves towards the observer, they squash up to a shorter wavelength the frequency increases and a high pitch sound is heard

Front 34

What is red shift? (1 mark)

Back 34

If a light source such as a galaxy is moving away from you, the wave is stretched out and becomes low frequency. Light appears to be redder

Front 35

How does red shift suggest that the universe is expanding? (3 marks)

Back 35

When looking at the light from distant galaxies, the wavelengths are shifted towards the red end of the spectrum compared with a stationary source on Earth.
Red is a longer wavelength, so the waves have been stretched out meaning that the galaxies are all moving away
As the galaxies are all moving away, then the universe is expanding. More distant galaxies have larger red shifts, so are moving away faster

Front 36

What evidence is there for the Big Bang? (2 marks)

Back 36

Red Shift
Across the whole universe cosmic microwave background radiation (CMBR) has been found

Front 37

What is cosmic background radiation (CMBR)? (1 mark)

Back 37

CMBR is a form of electromagnetic radiation filling the universe. It comes from radiation that was present shortly after the beginning of universe

Front 38

What happens when source is moving away from the observer? (1 mark)

Back 38

Wavelength increases and frequency decreases and source will appear as red shifted

Front 39

What happens when source is moving towards the observer? (1 mark)

Back 39

Wavelength decreases and frequency increases and sources will appear as blue shifted