Question

100 g of hot water at 90°C is mixed to 400 g of cold water at 10°C, the equilibrium temperature of
the mixture is:
(A) 26°C
(B) 45°C
(C) 60°C
(D) 50°C
​

Answer 1

Answer:

(D) 50°

Explanation:

Ta = 90°

Tb = 10°

Tavg = 90+10/2

= 100/2

= 50°

Answer 2

Answer:

Explanation:

400[t-10]=100[90-t]

4t-40=90-t

5t=130

t=26