Thu January 17, 2013 By: Sathish

while we stir hot water the water cools(temperature decreses), but in joules apparatus more or less the same thing is done,,,, but there temperature increses...why it is so

Expert Reply
Fri January 18, 2013
 joules apparatus is insulated from the surrounding.
so the heat inside does not go to the surrounding.
when we stir the liquid, the heat /extra energy gets distributed through out the liquid , in all molecules,so the thermometer may show sudden rise initially.
Where as in normal glass,it releases heat to the surrounding, temperature decreases.
Ask the Expert