If 200 grams of water is to be heated from 24.0oc to 100.0oc to make a cup of tea, how much heat must be added?

According to this formula:

Q = M*C*ΔT 

when we have M ( the mass of water) = 200 g 

and C ( specific heat capacity ) of water = 4.18 J/gC

ΔT (the difference in temperature) = Tf - Ti 
     
                                                          = 100 - 24

                                                          = 76°C

So by substitution:

Q = 200 g * 4.18 J/gC * 76 °C

   = 63536 J 

 ∴ the amount of heat which be added and absorbed to raise the temp from 24°C to 100°C is = 63536 J

The density of water is 1 g/cm cubed and in order for the pebble to sink its density has to be greater than the density of water and in order for the twig to float its density has to be less than the density of water