In this series entitled “Questions that I can’t answer a 10 year old …”, I will be documenting the questions posed by a 10 year old child which I was not able to answer right away.
Hopefully, through these series of articles, you will be able to have a glimpse of how children learn and how inquisitive they can be.
Background (The context that elicited this question)
I was teaching about the water cycle to my grade 4 student (10-11 year old). We were learning about condensation of water vapour into water droplets. The culmination of water droplets leads to the formation of clouds. He was having difficulty accepting that clouds are made of water droplets because they look so fluffy and light.
He’s right about it. Clouds do not look like water at all! Why can clouds “fly” or float in the air if they are water droplets? Why do the clouds not fall? I was caught off-guard when he posed the question.
I promised that I would read up about it and explain to him the next lesson. I googled the question and below is a summary of what I learnt. Hopefully, the next time if your child asks you this question, you could quickly give him/her an answer.
1. The vast majority of clouds you see contain water droplets and/or crystals that are too small and light to have any appreciable fall velocity individually.
2. The clouds look like they are floating in the air because the tiny water droplets are very spread out in the air which is usually moving upwards.
3. However, as the water droplets gather together, they become heavier as a whole and the droplets fall faster to the ground compared to when they are alone. This is why the clouds will fall onto the ground as rain or snow eventually.