Melinda filled two glasses equal size half-full with water. The water in one glass was 50 degrees Celsius. The water in the other glass was 10 degrees Celsius. She poured one glass into the other, stirred the liquid, and measured the temperature of the full glass of water. What do you think the temperature of the full glass of water will be after the water is mixed?

30 °C

Explanation:

When you pour water from one glass to the other, the heat energy will flow from the hot water to the cold.

You have equal masses of water in each glass. The hot water should cool down as much as the cold water warms up.

The final temperature should be halfway between the starting temperatures in each glass.

(10 °C + 50°C) / 2 = 60 °C/2 = 30°C

The temperature of the full glass of water should be 30 °C.