Geography KS3 / GCSE: Why does water fall as rain?

Richard Hammond demonstrates the effect of water on other physical objects.

Water weighs around one kilogram per litre. The annual rainfall of England's wettest place, Borrowdale in the Lake District, is placed into the bucket of a machine. This is then dropped onto a car, crushing it.

Richard then moves on to demonstrate the effect of air resistance on raindrops. He builds a series of sand castles at the base of a tower in Bristol. When water is dropped from waist height the sandcastle is crushed. When dropped from height (30 metres), the water has less effect. The effect of air resistance on water is therefore explained.

Teacher Notes

Key Stage 3

This short film provides a demonstration of water’s power and weight. Pause just before the bucket is tipped in order to ask your class to make predictions on what will happen to the car.

This provides a nice link to science / physics as well as geography. You could look up precipitation information for Borrowdale in the Lake District. Why doesn’t the rain crush us? Then play the Bristol part of the clip.

Key Stage 4

Students could explore various sources of information in order to produce an explanation of why Borrowdale is the wettest place in the UK, linked to relief rainfall and the rain shadow. What are the other climate variables there annually? Science students could talk about reliable experiment design.

Curriculum Notes

This topic appears in geography and physics at KS3 and KS4 in England, Wales and Northern Ireland and National 5 in Scotland.

At GCSE it appears in AQA, OCR A, EDEXCEL, EDUQAS, WJEC and CCEA, in SQA at National 5.

More from Richard Hammond's Wild Weather

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How does a thermal form?
How does hail form?
How to see thunder
How to use wind to forecast the weather
Inside a tornado
What is the difference between rain and drizzle?
What is wind?