Question

what would be the final temperature ofa mixture of 50g of water at 20 c temperature and 50g of water at 40c temperature

Answer 1

given mass m1=50g ,t1=20c
                  m2=50g ,t2=40c 
                 t=m1t1+m2t2/m1+m2
t=50*20+20*40/50+50
t=2000+1000/100
t=3000/100
therfore,t=30c

Answer 2

Since the mass is equal in both the cases
Final temperature=Average temperature of the 2 mixtures.
=50+30 /2
=40 degree C

Ans:40 degree C.