I magine you are making a hot drink. You are just about to add some milk when you realise that your neighbour is knocking at your door.
Should you add the milk now or wait until you have finished talking to your neighbour? Good question, time to do some research!
4 cups that are exactly of same size and same shape, Hot water, Cold water, Cold milk, A thermometer and Spoons.
Half fill each cup with hot water.
Check that all of the cups are at the same temperature. Leave the thermometer in one of the cups for now.
Add 1 spoon of milk to the first cup. Add 1 spoon of cold water to the second cup. Add 3 spoons of milk to the third cup. Don’t add anything to the last cup.
Check the temperature of each cup every minute with the thermometer. Which cup of water stays hot for the longest?
This one is up to you, do you think you can explain it?
Some other interesting questions related to this topic include:
What are some good ways of keeping drinks hot?
Have you heard of the word, ‘insulation’?
What happens if you want to keep a drink cool rather than hot?
Which is more likely to keep a drink hot for longer: a tall thin cup or a wide shallow cup?
Do some liquids cool faster than others?
What type of cup is better for keeping drinks hot: paper, plastic, clay or glass?
