# Forces and Mechanisms

## Unit Overview

In the Forces and Mechanisms project, children will revisit prior learning about forces, identifying what a force is and discussing the two types, including contact and non-contact forces. They will learn that gravity is a force of attraction and follow instructions to observe gravity in action. They will learn the meanings of the terms 'mass' and 'weight' and their units of measurement, following instructions to record the mass and weight of various everyday objects using a piece of equipment called a force meter. They will revisit learning about friction, discussing situations where it can be helpful or where we need to minimise its effects. They will learn about the frictional forces called air and water resistance in detail and conduct investigations to observe these frictional forces in action. They will learn about mechanisms, including gears, pulleys and levers and follow instructions to investigate how these simple machines use forces to make tasks easier.

β MEMORABLE MOMENT

To test the effect of air resistance on different sizes of parachutes.

οΈβοΈ WRITING OPPORTUNITIES

To write about each investigation discussing methods and conclusions.

π³ LEARNING OUTSIDE THE CLASSROOM

To create a test a pulley using broom sticks and rope.

### Unit Sequence: Learning Intentions

1. Contact and non-contact forces & Gravity - To use relevant scientific vocabulary to report on their findings, answer questions and justify their conclusions based on evidence collected, identify improvements, further questions and predictions. To explain that unsupported objects fall towards the Earth because of the force of gravity acting between the Earth and the falling object.

2. Mass and weight- To record data and results of increasing complexity using scientific diagrams and labels, classification keys, tables, scatter graphs, bar and line graphs. To take measurements, using a range of scientific equipment, with increasing accuracy and precision, taking repeat readings when appropriate.

3. Friction - To identify the effects of air resistance, water resistance and friction, that act between moving surfaces.

4. Air & Water resistance - To identify the effects of air resistance, water resistance and friction, that act between moving surfaces. To take measurements, using a range of scientific equipment, with increasing accuracy and precision, taking repeat readings when appropriate.

5. Levers, Pulleys & Gears - To recognise that some mechanisms, including levers, pulleys and gears, allow a smaller force to have a greater effect.

6. Quiz

### Scientific Enquiry: Investigations

1. What do pulleys do?

• To recognise that some mechanisms, including levers, pulleys and gears, allow a smaller force to have a greater effect.

π BIG FINISH

Quiz

π FOCUS TEXT(S)

Cosmic by Frank Cottrell-Boyce