In this lesson you are going to learn about conductors and insulators. Can you remember what these words mean? Conductors? Don’t they collect tickets on the bus? Hmmm and insulators are like the cotton wool in your head!
We are going to make a container that heats water using the Sun. Energy from the Sun will need to be transferred to the water. Then you can use the warm water to wash your hands. That sounds like fun but what does TRANSFER mean?
At home energy is TRANSFERRED in lots of ways. Look at this saucepan where potatoes are being boiled. Heat energy is being transferred from the electric ring to the glass hob. Heat energy is being transferred from the glass hob to the metal saucepan. Heat energy is being transferred from the metal saucepan to the water and potatoes. Then can I transfer the potatoes from the pan to my stomach?
3 1 2 gas water heater radiator room Radiator Here is another example. What do you think is going on? 1. Heat energy from burning gas in the heater is transferred to w _ _ _ _. 2. Heat energy from the hot w _ _ _ _ is transferred to the metal r _ _ _ _ _ _ _ . 3. Heat energy from the metal r _ _ _ _ _ _ _ is transferred to the r _ _ _ . a t e r a t e r a d i a t o r a d i a t o r o o m
What do we call things that allow heat energy to transfer easily? They are called conductors. Solid fuel stove Metal hob The heat energy is transferred from the burning fuel, to the metal hob, to the metal saucepan and kettle and then to the water. Heat energy is being transferred from the water to the spoon in the saucepan too. Good conductors feel cold when there is no source of heat. They don’t retain heat but let it be transferred away.
Sometimes we don’t want heat to be transferred, we want to keep the heat in. What do you know about all these things? Hats, coats, gloves and scarves are all insulators. They make it difficult for heat energy to be transferred from your body to the cold air, so they keep you warm.
Look at these things. These are insulators too. What do they do? Tea cosy, burger box and thermos flask all prevent the transfer of heat.
Look at these containers. They will be filled with hot water. Which ones do you think are conductors that will allow the transfer of heat energy most easily? How will I know which containers conduct heat energy most easily? glass Paper cup Clue Polystyrene cup Metalmug Pottery mug Plastic mug
Here is a fun activity. Use your fingers to find out which materials are good conductors and which are good insulators. Use a table like this one.
Materials that conduct or insulate are important parts of solar thermal collectors that heat water using the Sun’s energy. Look at this diagram of a solar thermal collector. Which parts are conductors and which are insulators? A. clear sheet of glass B. dark coloured metal C. metal water pipes D. thick board, such as polystyrene