Forces and Motion
Learning Objectives
- Know how balanced and unbalanced forces affect the motion of an object
- Describe factors which affect the size of frictional and drag forces
Skills focus
- Recording reliable data and draw valid conclusions
Lesson Description
In this lesson we explore the effect of balanced and unbalanced forces on movement. We ask the big question of how does the INEOS TEAM UK race boat manage to accelerate up to speeds of 60 mph powered only by the wind?
Students carry out a practical investigation into how the size of a force affects an object as it moves through the air. The resource comes with a Teacher PowerPoint presentation, introductory video, and printable template for use in the practical investigation.
This lesson is one in a series of five exploring forces through practical investigations linked to the real-life exciting context of the British America’s Cup Team.
Each lesson focuses on a series of key questions and is aimed at the knowledge and skills requirements of KS3 Science; it also has relevance for both Engineering and Design Technology students at KS4.

Learn about balanced and unbalanced forces and how these affect the movement of an object through the context of Britannia INEOS TEAM UK’s cutting edge race and pursuit boat.


KS3 Curriculum Links England
Motion and Forces
Describing motion
- Speed and the quantitative relationship between average speed, distance, and time (speed = distance ÷ time)
- The representation of a journey on a distance-time graph
Forces
- Forces as pushes or pulls, arising from the interaction between 2 objects
- Using force arrows in diagrams, adding forces in 1 dimension, balanced and unbalanced forces
- Moment as the turning effect of a force
- Forces: associated with deforming objects; stretching and squashing – springs; with rubbing and friction between surfaces, with pushing things out of the way; resistance to motion of air and water
- Forces measured in newtons, measurements of stretch or compression as force is changed
Pressure in fluids
- Pressure in liquids, increasing with depth; upthrust effects, floating and sinking
Balanced forces
- Opposing forces and equilibrium: weight held by stretched spring or supported on a compressed surface
Forces and motion
- Forces being needed to cause objects to stop or start moving, or to change their speed or direction of motion (qualitative only)
- Change depending on direction of force and its size
KS3 Curriculum Links Scotland
Forces: developing an understanding of how forces can change the shape or motion of an object and the forces acting on it, and developing an understanding of the concept of buoyancy, force and density.
Working scientifically
- Through the content across all five lessons students will develop:
Scientific attitudes
- Pay attention to objectivity and concern for accuracy, precision, repeatability and reproducibility
- Evaluate risks
Experimental skills and investigations
- Ask questions and develop a line of enquiry based on observations of the real world, alongside prior knowledge and experience
- Make predictions using scientific knowledge and understanding
- Select, plan, and carry out the most appropriate types of scientific enquiries to test predictions, including identifying independent, dependent, and control variables where appropriate
- Use appropriate techniques, apparatus, and materials during laboratory work, paying attention to health and safety
- Make and record observations and measurements using a range of methods for different investigations, and evaluate the reliability of methods and suggest possible improvements
Analysis and evaluation
- Apply mathematical concepts and calculate results
- Present observations and data using appropriate methods, including tables and graphs
- Interpret observations and data, including identifying patterns and using observations, measurements and data to draw conclusions
- Present reasoned explanations, including explaining data in relation to predictions and hypotheses
- Evaluate data, showing awareness of potential sources of random and systematic error
- Identify further questions arising from their results