Science/Physics KS2/KS3: Will pulleys let 9 year olds beat Britain’s strongest man?

After observing Britain’s strongest man pulling a 12 tonne truck a group of children are challenged to work as a team, using science, to pull the truck too.

An engineer from Sheffield University demonstrates how using pulleys can make it easier to lift a heavy weight.

After explaining what a pulley is, the children take part in a simple demonstration to show that the more pulleys you use, the easier it is to lift a weight.

This is explained as the weight being ‘shared’ between the pulleys. The more pulleys, and hence the more ropes, the easier it is.

Measurements are taken to quantify the relationship between the number of pulleys used and the distance that the weight is moved, e.g. with six pulleys the weight is lifted one sixth of the distance.

The children then apply this knowledge to help them complete the challenge of pulling the truck.

This short film is from the BBC series, Operation Awesome, in which students explore a range of amazing practical science challenges with presenter Steve Mould.

Teacher Notes

Key Stage 2

This short film could be used to introduce the idea that some mechanisms, including pulleys, allow a smaller force to have a greater effect.

Pupils could be set a challenge of their own to design and make their own pulley system to lift a heavy load.

They could research other examples found in history where pulleys were used e.g. pulleys were used to get water out of a well, or in constructing large buildings.

They could explore real life examples where pulleys are used today e.g. flagpoles, theatre curtains, window blinds etc.

Key Stage 3

This short film could be used to introduce the idea that simple machines give a bigger force but at the expense of smaller movement (and vice versa): product of force and displacement unchanged.

Pupils could carry out an investigation themselves using pulleys, measuring the size of the force and the distance moved for different numbers of pulleys, plotting the results on a graph, and calculating the work done to identify a pattern in the results.

They could explore and research more complex examples of pulleys in real life e.g. in exercise equipment, rock-climbing, cranes etc.

Curriculum Notes

This short film will be relevant for teaching science at Key Stage 2 or Second Level in Scotland, or physics at Key Stage 3 or Third Level in Scotland.