Hot mug challenge

The video and worksheet set out a measurement challenge for students that can be carried out at home or in school. Students use four different drinks containers to measure the rate of cooling of hot water to investigate how the material and use of a lid affects the process. A stainless steel insulated cup with lid, a paper cup without a lid, one with a lid, and a porcelain cup are required and ideally an infra red thermometer as its easier and more accurate to use. The same volume of hot water at the same initial temperature is poured into each and then the time taken for cooling from 60 °C to 50 °C noted on a table provided by the NPL. Similarly, the time taken for cooling from 50 °C to 40 °C is added to the table and readings submitted to the NPL website, via a link in the worksheet. This resource could be used as a context to investigate choice of materials to be used in new housing developments to prevent heat losses.