Question

gary drinks coffee with milk every morning. he notices that some mornings his coffee seems to cool down quickly and some mornings it seems to stay warm longer. he wonders what factors affect how quickly his coffee cools down. he has the following supplies available: two small coffee mugs, two large coffee mugs, hot caffeinated coffee, a pot, a stove, cold milk, a thermometer. using only these supplies, which two questions can gary investigate with an experiment? does a small mug of coffee stay warm longer than a large mug of coffee? does a small mug of coffee cool down more quickly if it is sweetened with sugar or if it is unsweetened? does a large mug of caffeinated coffee cool down more quickly than a large mug of decaffeinated coffee? does a small mug of coffee stay warm longer when warm milk is added instead of cold milk?

Explanation:

1. Gary has small and large coffee mugs, so he can test the effect of mug - size on cooling time.
2. He has cold milk, but no warm milk. Also, he has no sugar, and no decaffeinated coffee. So, questions about sweetening, caffeine content, and warm - milk addition cannot be investigated with the given supplies.

Answer:

Does a small mug of coffee stay warm longer than a large mug of coffee?