A great introduction to the topic of heat involves looking at and discussing a variety of devices which measure temperature or involve heat. This simply helps build up vocabulary on the topic and makes pupils aware of the devices all around them which can help with their understanding.
What do the numbers mean and why are there two different sets?
Why donít the numbers go above 50 on the left hand side?
What is the blue vertical line in the middle?
What is significant about the red zero?
What is the Boiling Point of water?
What is the temperature reading on this thermometer?
The thermometer on the left contains alcohol and red dye. The higher the temperature the further up the tube the red liquid rises. The liquid expands as it gets hotter. The two very small thermometers on the right are very accurate medical thermometers which contain a very special liquid metal called mercury. These medical thermometers have only a very small temperature range between 34 and 42degC - why?
Colour changing thermometer strips are used for small children when they are taken to hospital. They stick onto the forehead and the black bars change colour to indicate the body temperature. What is normal body temperature?
This is a fishtank thermometer. Look closely and you can see that the 19degC bar is lit up green and the 20degC bar is starting to change colour also. The temperature must be rising. The green bar is about to go dim and the brown bar about to change colour to green. Why is it important to know the temperature of the water for tropical fish? What is normal tapwater temperature?
This type of thermometer is often called a temperature gauge. A pointer is used to show the temperature reading on a circular numbered scale. They are normally used on machines or engines or large heating systems where a glass tube thermometer might easily get broken. The pointer and dial is also easier to read than the liquid level thermometer.
Which household appliance might have a temperature this high? 210degC. Why do we need such high temperatures?
Which household appliance might have a temperature this low? Why do we need such low temperatures? The rectangular box on the left of the display shows that this is the temperature in the top compartment. What might the temperature be in the bottom compartment of this appliance and why?
What is happening in this picture from outer space?
As the landing craft containing an exploration vehicle enters the atmosphere of the planet at great speed there is tremendous friction between the gas molecules in the atmosphere and the surface of the landing craft. This causes the whole outside of the craft to heat up to thousands of degC. Surely the inside of the craft containing the landing vehicle would simply melt! The outside of the craft has a very special heat resistant material covering it which is a very good insulator. This stops the heat from penetrating the craft.
The reason why scientists are very interested in the topic of heat is that they are searching for new materials to withstand intense heat and intense cold on Earth and on other planets. eg. in the Earthís core and at the North and South Poles.