In the unit Rope bridge students act as consultant engineers for a company who have to repair or replace a community’s bridge which has fallen into disrepair. They learn about the nature of forces, gravity and how to work with balanced forces to create stable structures. They work in teams to build a complete model bridge which they use, alongside a presentation, to explain to the local people where the bridge will be built why it will be constructed in that particular way.

Episode 1: Broken bridge

In this episode, the students look at the structures of various types of bridges and learn the correct meaning of the scientific term 'force'. They look at various ways to cross a canal or river and summarise the advantages and disadvantages of each approach.

Episode 2: Bridge designs

In Bridge designs students review some possible designs for the replacement bridge and use their growing understanding of forces and the way they act to identify the most promising approach. They carry out a scientific investigation into factors which affect the strength of a bridge and use this to inform their thinking and explain why bridges are designed in the way they are.

Episode 3: Gravity

In this episode students look at the connection between mass, weight and gravity and consider how the weight of the platform on a rope bridge affects the usefulness of the bridge and the number of people who could cross at any one time.

Episode 4: The model bridge

In this episode students construct a model of their proposed bridge to show the local people how it will work and explain the scientific and engineering decisions behind the bridge's construction. The students also produce a formal presentation to further emphasise the science involved in their bridge designs.

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