An electric kettle (marked 3 kW) produces
3000 joules of heat every second. It is filled
with water, weighed and switched on.
After coming to the boil, it is left on for a
further 80 seconds and then switched off. It
is found to be 100 g lighter.
Calculate the specific latent heat of steam.
Suggest reasons why your answer does not
agree with the accepted value.