Hello there,

please make me clear​

my doubt is,
to find the Calorific value of any kind of fuel, it is measured via heating water.
the equation used is,
Q = m x s x t

m = mass of water in grams

s = specific heat of water = 4.2.J/gm x °C

t = rise in temperature of the water.

i want to know , how the value of 4.2.J/gm x °C is obtained for water.
please ,let me know the exact derivation behind it.
or give me link,from where i can get the information.
--------- advance thanks.------------

 

The energy figure is that amount of energy that is require to increase the temperature of one gram of water by 1 deg. C - http://hyperphysics.phy-astr.gsu.edu/HBASE/thermo/spht.html

 

It isn't "derived", it's found by making an experimental measurement. A known mass of water has a known amount of energy dumped into it and the temperature rise of the water is measured.

You could make the measurement yourself if you're so inclined -- here's a site that gives a method.

 

thank you , i found it.