# Moments and machines teaching resources

##### Worksheets and lesson ideas to challenge students aged 11 to 16 to think hard about moments (GCSE and Key Stage 3)

Moments are an exciting area of Physics. They provide students with an understanding of every day experiences such as see-saws,using spanners, cranes and opening doors. It is best to refer to moments as clockwise and anticlockwise rather than moments on the left and right. This is a great video to demonstrate how distance and force affect the size of the moment. You can get students to experience this effect in the classroom by getting them to open doors at various distances from the hinge (pivot); they will be able to feel the difference in the force required to open the door.

#### Where to start?

Students will encounter levers in their daily lives but won’t appreciate what they are or how they work. A great starting point is to challenge two students to hold the same masses placed in four shopping bags. One student holds two bags with arms stretched out. The other student has the plastic bags hanging at the elbow joint. Who can hold the weight the longest? This can then lead to a discussion as to why it required less effort when the plastic bags were closer to the shoulder (pivot), eventually leading to an understanding that work done = force x distance.

#### Levers and moments: work done = force x distance

GCSE worksheet to help students understand levers and moments. Students work in small groups to work through some thinking problems about levers, moments and machines. (PDF)

This fantastic film explains the power of the mighty lever. How long would a lever have to be for a person to lift a smart car? Or for the same person to lift a 2.5 tonne truck? It’s a great example of how a simple machine can achieve something incredible. This second clip introduces input work and output work through the relationship, work done = force x distance and helps students to understand the trade-off between force and distance.