Revise GCSE Physics


Question: What does the following graph tell us about the rate of cooling of water?

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Graph showing how the temperature of a beaker of hot water changes when left alone (outside on a winters day).

Poor Answer: The rate of cooling is highest at the beginning of the graph because this is when the temperature of water is highest.

Good Answer: The rate of cooling is greatest at the starting time because this is when there is the greatest temperature difference between the water and the surroundings.

Note: It is best to write about Temperature Difference not highest temperature and discuss starting the time not just the start of the graph.