Light and Colour Summative 2

Question 1

The electromagnetic spectrum

Answer 1

The energy released from the sun is called electromagnetic radiation. Visible light is a form of electromagnetic radiation.

Other radiation include gamma rays, UV radiation, infrared radiation, microwaves and radio waves.

All types travel as waves at the speed of light. The waves are all types of light, however they vary in wavelength and frequency.

Question 2

Transverse waves

Answer 2

Where particles vibrate back and forth in a different direction (up/down) to the direction of the wave motion (left to right).

Question 3

Longitudinal Waves

Answer 3

Where the particles vibrate back and forth in the same direction (left/right) of the wave motion.

Question 4

Transverse wave features

Answer 4

Crest: Highest point of the wave

Trough: Lowest point of the wave

Amplitude: Its maximum disturbance from its undisturbed position

Wavelength: The distance between two consecutive points of a wave. (measured in metres)

Frequency: The number of waves that pass a certain point each second. (measured in Hertz/Hz)

Question 5

Properties of light

Answer 5

Light is a form of energy that makes up part of the electromagnetic spectrum.

Light travels as a wave and can pass through a vacuum. (no air present).

Question 6

White light

Answer 6

White light is made up all the colours of the visible spectrum.

Question 7

When light hits a surface it can be:

Answer 7

Transmitted – (passes through)

Reflected – (bounced off)

Absorbed

Question 8

Transparent

Answer 8

All light can pass through
E.g. glass, water

Question 9

Translucent

Answer 9

Some light can pass through
E.g. lenses, frosted glass

Question 10

Opaque

Answer 10

No light can pass through

Question 11

Reflection

Answer 11

Regular reflection occurs when light reflects off a very smooth surface
A clear image is produced because the light rays bounce off at the same angle

Question 12

The law of reflection

Answer 12

The law of reflection states that the angle of incidence (incoming ray) is equal to the angle of reflection (outgoing ray). Therefore, i = r

Question 13

Plane mirrors

Answer 13

A flat mirror is called a plane mirror

Question 14

Refraction

Answer 14

Refraction is the bending of light

This occurs because when light travels from one transparent substance to another it will refract

This occurs because light travels at different speeds when passing through different substances

Question 15

Refractive index

Answer 15

If the light hits a more dense substance it will refract towards the normal line

Refractive index is a measure of how difficult it is for light to travel through that substance.

Question 16

Depth illusions

Answer 16

When you look at the light your brain traces the light reaching your eye in a straight line path, hence making the fish appear closer to the surface