Refraction When light rays enter and leave different substances they are bent. This is called refraction.

Refraction This diagram shows what happens to light which is reflected by the pencil. The light bends when it leaves the water. Your brain thinks that light always travels in straight lines so the pencil tip seems to be nearer the surface than it really is.

Pencil trick When a pencil is put into a beaker of water it looks ______. This is because the light is __________ as it leaves the water. The light travels _________ in air than water slower reflected bent faster refracted Choose three of these words to complete the sentences

Pencil trick When a pencil is put into a beaker of water it looks bent. This is because the light is refracted as it leaves the water. The light travels faster in air than water slower reflected Choose three of these words to complete the sentences

A Trick Question Ben put a coin in a mug and moved back so he could not see it. His friend Martin poured some water into the cup and suddenly Ben could see the coin again without moving. Why could Ben now see the coin?

The light had been refracted by the water:

Investigation air glass normal ray box

This is the bending of light rays Happens because the rays change speed. When they enter a more dense medium (glass, water,) they slow down. When they enter a less dense medium – like air, they speed up.

Refraction As the light ray enters the glass block it bends. This is called refraction. The light ray refracts towards the normal as it enters the block and away from the normal as it leaves the glass block. The light is refracted because it travels slower in the glass block than air.

Total internal reflection and refraction When an object is viewed through water the image we see is changed because of the way light waves behave as they pass from the water into the air.

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Conclusion Copy the following sentences into your notes choosing the correct answer. I noticed that the ray of light is refracted (away from/towards) the normal when it goes into a glass block. The ray of light is refracted (away from/towards) the normal when it comes out of a glass block. The ray coming out of the glass block is (parallel/at right angles) to the ray going into the block.