Question

Why are we able to sip hot tea or milk faster from a saucer rather than a cup?

Answer 1

Hint: A liquid has a larger surface area in a saucer than in a cup. One of the factors affecting evaporation is surface area. Larger is the surface area more is the evaporation.

Complete step by step solution:
If the hot tea (or milk) is taken in a cup, then due to the narrow shape of the cup, the surface area of hot tea (or milk) in the cup is comparatively small.
Because of the small surface area, the evaporation of hot tea (or milk) taken in the cup is slow, cooling caused by evaporation is less.
Hence the hot tea (or milk) remains appreciably hot for a much longer time, making it difficult to sip.
On the other hand, saucer has a large surface area
Due to the large surface area of hot tea (or milk) taken in the saucer, the evaporation of hot tea (or milk) from the saucer is faster.
The faster evaporation cools the hot tea (or milk) much more quickly making it convenient to sip (or drink).

Hence, we are able to sip hot tea or milk faster from a saucer than a cup.

Note: Students can confuse the concept of evaporation, make sure to remember that larger is the surface area more is evaporation.Evaporation happens when a liquid substance becomes a gas. When water is heated, it evaporates. The molecules move and vibrate so quickly that they escape into the atmosphere as molecules of water vapor