Light 2 Light is a form of energy Crookes Radiometer proves light has energy Turns in sunlight as...

Light

2

Light is a form of energyCrooke’s Radiometer proves light has energy

Turns in sunlight as the light heats the black side

3

Shadows Light travels in a straight line.

If something gets in its path the light is blocked.

A shadow is formed.

4

Eclipses

Proves light travels in straight lines

5

Light travels in straight lines

6

Light on cards goes through if the cards are lined up. This also proves light travels in straight lines

7

Reflection

Incident ray

Normal

Reflected ray

Angle of incidence

Angle of reflection

Flat Mirror

Angle of incidence = Angle of reflection

8

Image Here in a plane mirror an

image is formed by the eye Can not appear on a screen

d d

9

Refraction

Fisherman use a trident as light is bent at the surface

The fisherman sees the fish and tries to spear it

10

11

Refraction through a glass block

Light bends towards the normal

12

Real and Apparent Depth

A pool appears shallower

13

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Focal Point

Focal Point

Lenses Two types of lenses

Converging Lens Diverging Lens

15

Dispersion

Breaking up of white light into it’s colours

16

Electromagnetic spectrum

Gamma rays

X-rays Ultra violet

Visible light

Infra red Microwaves

Radio/TV

Each type of radiation shown in the electromagnetic spectrum has a different wavelength and a different frequency:

High frequency, short wavelength

Low frequency,long wavelength

γ

The higher the frequency of the wave, the greater its energy. This makes X-rays dangerous and radio waves

safe

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Primary and secondary colours

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UHF and VHF