Joule’s experiment

HOW

Turn the crank and read the temperature on the display.

WHY

The device contains a liquid tank, similar in design to a flask. Inside it is a mixer that rotates when you turn the crank. As the mixer blades strike the liquid particles, their average velocity increases. How fast the particles move is closely related to their temperature. A higher average speed means higher temperatures.

NOTE!

If the station has not been used for some time, the temperature may initially drop. This is because, in a stabilised liquid, the higher layers of the liquid in which the thermometer is located may have a slightly higher temperature compared to the lower layers. When you start turning the crank, the temperature equalises. For the upper layers of liquids, this means a drop in temperature.