# Light waves Flashcards Preview

## Year 7 Science Flashcards Ms Lee > Light waves > Flashcards

Flashcards in Light waves Deck (28)
1
Q

What is a wave?

A

Waves are one of the ways in which energy may be transferred between energy stores.

2
Q

How could you describe a wave?

A

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

3
Q

What are mechanical waves?

A

Mechanical waves: are waves that require a medium e.g. air/water. This means that they have to have some sort of matter to travel through.

4
Q

What are electromagnetic waves?

A

Electromagnetic waves: are waves that can travel through a vacuum (empty space). They don’t need a medium or matter.

5
Q

Give an example of a longitudinal wave.

A

Sound waves are longitudinal waves.

6
Q

Give an example of a transverse wave.

A

Light waves are transverse waves.

7
Q

What is the direction of travel of the vibrations in a longitudinal wave?

A

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

8
Q

What is the direction of travel of the vibrations in a transverse wave?

A

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

9
Q

What is the peak of a wave?

A

Peak - the highest point of a wave (above the rest position).

10
Q

What is the trough of a wave?

A

Trough - the lowest point of a wave (below the rest position).

11
Q

What is meant by the ‘amplitude’ of a wave?

A

Amplitude - the distance from the middle of a wave to the top (peak) or bottom (trough) of a wave. The ‘loudness’ of a sound.

12
Q

What is a wavelength?

A

Wavelength - the distance from one point on a wave to the same point on another wave. Usually measured from peak to peak, or trough to trough

13
Q

What is frequency of a wave?

A

Frequency - the number of waves passing a particular point each second. Frequency is measured in hertz (Hz). The pitch of a note depends on it’s frequency.

14
Q

What is the difference between transparent and translucent materials?

A

A transparent material lets almost all the light pass through whereas a translucent material only allows some of the light through.

15
Q

Can light travel through an opaque material?

A

No, an opaque material does not allow light to pass through. e.g. wooden table, mirror

16
Q

What is a luminous object?

A

Luminous objects are objects that give out their own light e.g. the sun, candle flame.

17
Q

Define specular reflection

A

Reflection from a smooth, flat surface is called specular reflection. This is the type of reflection that happens with a flat mirror.

18
Q

Define diffuse scattering in terms of reflection

A

If a surface is rough, diffuse reflection happens. Instead of forming an image, the reflected light is scattered in all directions.

19
Q

What does the law of reflection state?

A

‘’when light is reflected from a smooth surface e.g. a mirror, the angle of incidence is equal to the angle of reflection.’’

20
Q

What is meant by the term ‘refraction’ of light.

A

Refraction of light is the BENDING of light when it passes from one medium (e.g. air) to another medium (e.g. water).

21
Q

The image shows a transverse wave. What is label W the image?

A

Peak/crest

22
Q

The image shows a transverse wave. What is label Y the image?

A

Trough

23
Q

The image shows a transverse wave. What is label Z the image?

A

Wavelength

24
Q

The image shows a transverse wave. What is label X the image?

A

Amplitude

25
Q

What are the 7 colours of white light?

A

Red, orange, yellow, green, blue, idigo and violet

26
Q

When white light passes through a _____________ it splits into it’s 7 different colours.

A

Prism

27
Q

The splitting of white light when it passes through a prism is called _____________.

A

Dispersion

28
Q
A