z Light, sound and heat are all forms of energy. z We see objects because light reflects off them and travels into our eyes.
z Diffuse reflection happens when light bounces off a rough surface in all directions.
z Regular reflection happens when light bounces in one direction off a smooth surface.
z Refraction is the bending of light as it passes from one medium to another.
z The eye allows us to see objects by using a lens system to focus light onto the retina.
z White light can be split into a spectrum of seven colours using a prism. This is called dispersion.
z Red, green and blue are primary colours. Combined, they produce white light.
z Yellow, cyan and magenta are secondary colours. Each one is formed from combining two primary colours.
z Objects appear as certain colours because they absorb all the colours in white light except their own. This colour is reflected.
The BIGChallenge
The management of your school canteen is planning to introduce hot drinks to the menu, but it is uncertain about the best cups and accessories (such as lids and sleeves) to use. It needs cups that will keep soups, teas and hot chocolates hot for the longest period of time.
Create a leaflet advising the canteen management on the best types of cups and accessories to buy.
Your leaflet must be
informed by the factors that affect the rate at which heat is lost.
Make sure your findings are communicated in a clear way.
