Light travels very fast in straight lines. We see objects because they reflect light into our eyes, forming shadows where light is blocked. Reflection follows the law that the angle of incidence equals the angle of reflection. Sound travels slower than light and we hear things when they vibrate at different frequencies and amplitudes. The ear contains structures like the eardrum, bones and cochlea that help detect and process sound vibrations.

18. A white hat would reflect all seven colours: A pair of purple trousers would reflect purple light (and red and blue, as purple is made up of red and blue): Purple light White light

21. Some further examples: Red Blue Red Blue Black Red Blue Red Red Black Blue Green Magenta book Green Green camel Green Blue teddy Black Green Red socks Colour object seems to be Colour of light Object Homework

23. Investigating filters Yellow Magenta Cyan Blue Green Red Colours that could be “seen” Colour of filter

24. Red Magenta White Yellow Blue Green Cyan

25. Refraction Refraction is when waves ____ __ or slow down due to travelling in a different _________. A medium is something that waves will travel through. When a pen is placed in water it looks like this: In this case the light rays are slowed down by the water and are _____, causing the pen to look odd. The two mediums in this example are ______ and _______. Words – speed up, water, air, bent

28. Sound – The basics We hear things when they vibrate . If something vibrates with a high frequency (vibrates very ______) we say it has a _____ pitch. If something vibrates with a low frequency (vibrates ______) we say it has a ____ pitch. The lowest frequency I could hear was… Words – slowly, low, high, quickly

29. Drawing sounds… This sound wave has a _____ frequency : This sound wave has a ___ _frequency :

30. Drawing sounds… This sound wave has a _____ amplitude (loud): This sound wave has a _____ amplitude (quiet):

33. The Ear Label your diagram with the following: These bones are vibrated by the eardrum This tube carries the sound towards the eardrum This part is used to help us keep our balance This part “picks up” the vibrations This part of the ear contains many small hairs with turn vibrations into an electrical signal This part connects the ear to the mouth This part “channels” the sound towards the ear drum

34. The Ear