Which cup keeps your coffee hot the longest ?

If you buy coffee at a motorway service station it often seems to be hotter than usual. Is this really the case ? The same amount (100 cm3) of hot water was placed into three different types of coffee cup: a bone china cup; a paper cup (with plastic lid); and a polystyrene cup (also with a plastic lid). A temperature sensor was placed in each cup and the data-logger began to record the temperatures.

 

Which cup kept the coffee hot for the longest time ? Do you think the lids made a difference - if they did, how did they make a difference ? The water in the paper and polystyrene cups starts at about the same temperature, but the first reading of the china cup is at a lower temperature (although the same temperature water was put into the cups) - why is this ? Why was it important to use the same amount of water for each cup ? Why was it better to use a computer to take these readings instead of just using a thermometer ?

You can get the raw data here: