mother and son
Image captionIn a survey, many parents admitted giving incorrect answers to children’s science questions

Why do cats have tails? How can you hear the train arriving before it gets to the station? Why don’t wind turbines in the sea sink with the weight?

These are just a few of the questions posed by parents who took part in an online question-and-answer session run by Mumsnet and the Institution of Engineering and Technology (IET) on Wednesday.

As part of Tomorrow’s Engineers Week, the organisations got to together to helpparents who were stumped when their children asked questions about science, maths and engineering matters.

The BBC News website has compiled some of the questions and answers.

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What is fog made from?

Tiny droplets of water float in the air and scatter light.

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catImage copyrightAlexandrum79

Why do cats have tails?

It is an extension of their spine. It helps with balance and aids communication.

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What causes lightning?

Hailstones bring driven up and down by strong winds in thunderstorms and crashing in to each other build up an electric charge. That eventually leads to a big spark of lightning (mostly between the top and bottom of the cloud but sometimes down to the ground).

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wind turbinesImage copyrightanderm

Why don’t wind turbines in the sea sink with the weight?

They are standing on the bottom of the sea.

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Are there any living organisms in the Earth’s core?

We know the Earth’s core is so hot it would be difficult for any living organisms as we know them to survive. However, in the outer crust of the Earth, there are some bacteria and organisms that live far below the surface.

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moonImage copyrightfirstpentuer

Why is the sky so light some nights and so dark on others?

Light bounces off clouds and makes the sky look less dark. On clear nights, it looks a lot darker.

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Will we soon have toys that can learn?

Engineers are developing robots that can learn from their experiences.