Question

Pat pours cold, liquid cream into a cup of hot coffee. Which of the following describes how the hot coffee and cold cream will interact?

Answer 1

heat will go from hot coffee to the cold cream and vise versa

Answer 2

The cold cream will drop to the bottom of the cup. When it warms, some of it will rise back to the surface.

Explanation

Convection is what drives the spread of the cold cream through the hot coffee. Since the cold cream is denser than the hot coffee, it will drop to the bottom of the cup. The cream's density will decrease as it warms. Once the cream at the bottom warms past a certain point, its density will be low enough that some of it will rise back to the surface.