Light and Sound

Question 1

What is light?

Answer 1

Light is a transfer of energy from one store of energy to another.

Question 2

Does light ever curve?

Answer 2

No, it always travels in straight lines.

Question 3

When will light stop travelling?

Answer 3

When it hits a non-transparent object.

Question 4

What to do when drawing ray diagrams

Answer 4

Use a ruler and use arrows to indicate directions.

Question 5

What happens when light hits a transparent surface?

Answer 5

The light hits it and passes through (it gets transmitted).

Question 6

What happens when light hits an opaque surface?

Answer 6

The light hits it and stops (it gets absorbed).

Question 7

What happens when light hits a reflective surface?

Answer 7

The lights hits it and bounces off (it gets reflected/scattered).

Question 8

What do luminous objects do?

Answer 8

They give off light.

Question 9

How do we see luminous objects?

Answer 9

When the light it emits enters our eye.

Question 10

Why does light from the sun travel in all directions?

Answer 10

The sun is a sphere.

Question 11

What is the angle of reflection equal to?

Answer 11

The angle of incidence.

Question 12

What is refraction?

Answer 12

The change in direction of a wave when it changes speed, typically when moving from one medium to another.

Question 13

What happens to a light wave if it slows down?

Answer 13

It bends towards the normal.

Question 14

What happens to a light wave if it speeds up?

Answer 14

It bends away from the normal.

Question 15

What is the slowest matter that light travels through?

Answer 15

A solid.

Question 16

What is the fastest matter that light travels through?

Answer 16

A gas.

Question 17

What matter does light travel through that is slower than a gas but faster than a solid?

Answer 17

A liquid.

Question 18

What colours can our eyes detect?

Answer 18

Red, green and blue.

Question 19

What do you get if you mix red and green light?

Answer 19

Yellow light.

Question 20

What do you get if you mix red and blue light?

Answer 20

Magenta light.

Question 21

What do you get if you mix blue and green light?

Answer 21

Cyan light.

Question 22

If you mix 2 colours of light, will it get brighter or darker?

Answer 22

Always brighter.

Question 23

What colours are you able to see in white light?

Answer 23

All of them.

Question 24

What is sound caused by?

Answer 24

Something vibrating?

Question 25

Can sound travel through a vacuum?

Answer 25

No.

Question 26

Does light travel faster than sound?

Answer 26

Yes.

Question 27

Why does sound travel?

Answer 27

It makes nearby particles vibrate.

Question 28

Longitudinal waves

Answer 28

When particles vibrate in the same direction as the wave travels.

Question 29

Compression

Answer 29

Increase in pressure and density of the air particles around it.

Question 30

Rarefraction

Answer 30

Decrease in pressure and density of the air particles around it.

Question 31

Frequency

Answer 31

The number of waves per second.

Question 32

The highest point in a sound wave

Answer 32

The peak.

Question 33

The lowest point in a sound wave

Answer 33

The trough.

Question 34

Amplitude

Answer 34

Half the full wave height

Question 35

Where the waves stop

Answer 35

Rest position/ Equilibrium

Question 36

The larger the amplitude…

Answer 36

The louder the sound.

Question 37

The greater the frequency…

Answer 37

The higher the pitch.

Question 38

What does sound travel fastest through?

Answer 38

A solid.

Question 39

What does sound travel slowest through?

Answer 39

A gas.

Question 40

What matter does sound travel through that is slower than a solid but faster than a gas?

Answer 40

A liquid.