WAEC - Physics (2014 - No. 21)
A quantity of water at 20oC is mixed with another quantity of water at 70oC. The final steady temperature of the mixture is 40oC. Determine the ratio of the mass of the cold water to that of the hot water
7:2
3:2
2:5
1:2
คำอธิบาย
Q = MC\(\theta\)
M = \(\frac{Q}{C\theta}\)
\(\frac{Q}{20C}\) : \(\frac{Q}{30C}\)
= 3:2
M = \(\frac{Q}{C\theta}\)
\(\frac{Q}{20C}\) : \(\frac{Q}{30C}\)
= 3:2