Question

Maria and Elena are supposed to help their mom cool some sodas by putting the cans in a big bucket full of ice, except that

Maria forgot to fill the ice trays. Elena says that she remembers reading somewhere that hot water freezes faster than
cold water. Maria is skeptical. She learned in her science class that as a liquid is hotter, its molecules move more quickly.
Since the hot water molecules have to further reduce their speed than cold water molecules to become ice, Maria thinks it
will take more time for hot water to freeze than for cold water. The girls decide to conduct a science experiment to
determine if it is faster to make ice cubes with hot water or with cold water.
Now, answer the following questions about the process they used to reach their conclusion.
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1. What is the question that Maria and Elena want to answer when doing the experiment?
a) Which water freezes more quickly?
b) Is hot water colder than cold water?
c) Does water temperature affect freezing time?
d) How much ice can each type of water produce?

Answer 1

The question that Maria and Elena want to answer when doing the experiment is "Does water temperature affect freezing time"? (Option C). They are trying to determine if the temperature of the water affects how quickly it can be turned into ice cubes.

Step-by-step explanation:

Maria and Elena's experiment aims to answer whether water temperature affects the speed of freezing, referred to as the Mpemba effect.

The physics concept of specific heat explains why water can have a greater cooling effect than ice on a hot piece of metal.

From a physics perspective, the concept at play here is related to the molecular movement of water molecules. Hot water molecules move more rapidly than cold water molecules.

When hot water is cooled, it must undergo a greater reduction in molecular speed to reach the freezing point compared to cold water.

However, the counterintuitive phenomenon known as the Mpemba effect suggests that, under some conditions, hot water may freeze faster than cold water.

When comparing the cooling effects of ice and cold water on hot metal, option a. Water would reduce the metal's temperature more, because water has a greater specific heat than ice.

This means that for the same amount of heat transfer, water will not change temperature as much as ice, since it can absorb more heat without a large temperature increase.

Hence, the correct answer is Option C.