Question

the temperature of 600 gram of cold water rises by 15 degree Celsius when 300 gram of hot water at 50 degree Celsius is added to it what was the initial temperature of cold water

Answer 1

we know the quantities from the question
mass of cold water {m2}=600gms
mass of hot water{m1}=300gms
temperature of hot water {T1}=50 K
change in temperature of cold water=T-T2=15 K
final temperature= TK
acc. to princeple of calorimetry
heat lost by hot body is equal to heat gain by cold body
therefore, Q of cold water= Q of hot water
therefore, m1c [T1-T} = m2c{T-T2}
              300  [50-T]=  600 [15]
                  T=20 K
given changer in temperature=15 K
therefore, initial temperature of cold water=20-15
                                                                    =5K