Waves

Question 1

What is frequency measured in?

Answer 1

Hertz (Hz)

Question 2

What is wavelength measured in?

Answer 2

Metres (m)

Question 3

What is the wave equation?

Answer 3

v = f x lambda Velocity (m/s) = Frequency (Hz) x Wavelength (m)

Question 4

What is a transverse wave?

Answer 4

-One that looks like a snake. -The oscillations are at right angles (perpendicular) to the direction of travel -Electromagnetic Waves (No medium)

Question 5

What is a longitudinal wave?

Answer 5

-One that has compressions and rarefactions. -The oscillations go in the same direction as the wave. -Sound

Question 6

Give some examples of a transverse wave:

Answer 6

-Light -Microwaves -Infrared -Radio -Water waves

Question 7

Give some examples of a longitudinal wave:

Answer 7

-Sound -Pressure (Shock) Waves

Question 8

What is wavelength?

Answer 8

The distance between two corresponding points on a wave diagram. E.g. From crest to crest.

Question 9

What is amplitude?

Answer 9

Amplitude is the length between the node (middle line) and the crest of a wave.

Question 10

What is a crest and a trough?

Answer 10

Crest - The top of a wave Trough - The bottom of a wave

Question 11

What do waves do?

Answer 11

Transfer energy, not matter. That medium always returns to its original place.

Question 12

What is frequency?

Answer 12

The number of wave crests passing a point every second.

Question 13

What is the speed equation?

Answer 13

Speed = Distance / Time

Question 14

Waves travelling from low to high density…

Answer 14

Slow down and bend towards the normal

Question 15

Waves travelling from high to low density…

Answer 15

Speed up and bend away from the normal

Question 16

What happens to wavelength when waves enter a material of higher density?

Answer 16

It decreases

Question 17

What do water waves do when going from deep to shallow water?

Answer 17

They slow down and bend towards the normal.

Question 18

What is diffraction?

Answer 18

The spreading out of waves after passing through a gap.

Question 19

When is diffraction most effective?

Answer 19

Wavelength smaller than gap - Little diffraction Wavelength bigger than gap - Lots of diffraction Large wavelength - Lots of diffraction generally

Question 20

What are the parts of the eye?

Answer 20

Question 21

What does the iris do in the eye?

Answer 21

Controls the amount of light which goes into the eye by expanding and detracting

Question 22

What does the cornea do in the eye?

Answer 22

• Protects the eye (aqeous humour)
• Refracts the light to the lens

Question 23

What does the lens do in the eye?

Answer 23

Focuses the image onto the retina

Question 24

What do the ciliary muscles do in the eye

Answer 24

Control the power of the lens

• More powerful - relaxed (bigger curve)
• Less powerful - contracted (smaller curve)

Question 25

What does the retina do in the eye?

Answer 25

Turns light (EM radiation) into an electrical signal

Question 26

What part of the eye sends the electrical signals to the brain?

Answer 26

Optic nerve

Question 27

What is another word for being short sighted?

Answer 27

Myopia

Question 28

What is the technical term for having long sightedness?

Answer 28

Hypermetropia

Question 29

What causes myopia?

Answer 29

* Cornea is curved too much * Lens is too powerful

Question 30

Where does myopia cause the image to be formed?

Answer 30

In front of the retina, far objects appear blurred

Question 31

What causes hypermetropia?

Answer 31

* Lens or cornea is not powerful enough

Question 32

Where does hypermetropia cause the image to be formed?

Answer 32

Behind the retina, near objects appear blurred

Question 33

What is the far point of a persons vision?

Answer 33

The furthest distance that an unaided eye can focus a clear image