Question

what would be the final temperature of a mixture of 100g of water at 90 degree c temperature and 200g of water at 60 degree c temperature​

Answer 1

Let final Temperature = T

Here heat lost by 100 g at 90° = heat gained by 600 g at 20°

Now by the formula,

100 × S × ( 90° - T ) = 600 × S × ( T- 20° )

(90° -T) = [600 × S × (T-20°)] / (100 × S)

⇒ 90° - T = 6(T - 20°)

⇒ 90° - T = 6T - 120

⇒ 120 +90 = 7T

7T = 210

T = 210/7

T = 30°

Hence the final temperature of the mixture is 30°