Question

What would be the final temperature of a mixture of 50g of water at 20 degree c temperature and 50g of water at 40 degree c temperature?

Answer 1

Given Mass (M₁) = 50g
Temperature (T₁) = 20° C
Mass (M₂) = 50g
Temperature (T₂) = 40°C
By using the method of mixture , Final temperature (T) = (M₁T₁+M₂T₂)/M₁+M₂
                                                                                = (50×40+50×20)/50+50
                                                                                = 3000/100
                                                                                = 30°C .

Answer 2

Given mass m1 = 50 grams
Temperature T1 = 20° C
Mass M2 = 50g
Temperature T2 = 40° C
then, 
Final Temperature = M1T1 + M2T2 / M1+M2
                         = (50×20+50×40)/50+50
                                = 1000+2000/100
                                = 3000/100
                                = 30° C .
Therefore, Final Temperature T= 30° C