Investigating Friction

Lesson Overview

Duration: 60 minutes
Class Size: 30
Year Group: Year 7 (Ages 11-12)
Set: 2

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National Curriculum References

• KS3 Science – Forces and Energy
  • Pupils should be taught to:
    • Understand that forces can affect the shape and motion of an object.
    • Describe friction as a force that acts between surfaces in contact; recognise how friction can be helpful or problematic.
• Working Scientifically
  • Plan enquiries, including recognising and controlling variables where necessary.
  • Take measurements, using a range of scientific equipment, with increasing accuracy and precision.
  • Record data and results of increasing complexity using scientific diagrams and labels, classification keys, tables, scatter graphs, bar and line graphs.
  • Use test results to make predictions to set up further comparative and fair tests.

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Learning Objectives

By the end of the lesson, students will:

1. Define friction and explain its role as a force acting between surfaces in contact.
2. Investigate how friction varies with different surfaces and apply this understanding in practical enquiry.
3. Demonstrate accurate measurement skills using force meters and recording results appropriately.
4. Analyse results to identify patterns, drawing conclusions about the effects of surface texture on friction.
5. Understand friction’s practical implications in everyday life and engineering.

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Key Vocabulary

• Friction
• Force
• Surface texture
• Contact forces
• Variable
• Measurement
• Fair test
• Coefficient of friction (introduced conceptually)

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Resources Needed

• Wooden ramp or flat board (~1m length)
• Various surface materials (felt, sandpaper, plastic sheet, smooth wood, rubber mat)
• Newton meters (spring scales) or force meters (30, one per pair)
• Objects to pull (wooden blocks of uniform size/weight)
• Stopwatch (optional for discussion of speed and friction)
• Whiteboard and markers
• Student worksheets for recording data and observations
• Safety goggles (if required by local policy)

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Lesson Structure

1. Starter Activity (10 minutes)

Engage:

• Pose a question to the class: "Why do some shoes slip on ice, but not on carpet?"
• Elicit brief ideas about slipperiness and grip, leading to the concept of friction.
• Show a quick demonstration: drag a wooden block across different surfaces (table, carpet, sandpaper) and feel the resistance.
• Introduce the term friction and clarify that it is a force that opposes motion between surfaces in contact.

Link to Learning Objective: Understanding friction as a force and its real-world relevance.

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2. Main Activity: Practical Enquiry (35 minutes)

Objective: Investigate how friction changes with different surfaces by measuring the force required to pull an object.

Steps:

• Set up: Students work in pairs; each pair uses a wooden block, force meter, and surface samples.

• Task Explanation:

  • Pull the block across each surface at constant speed using the force meter.
  • Record the force reading for each surface type.
  • Repeat each trial thrice for accuracy and calculate the average force.

• Fair Test Discussion:

  • Ensure the block’s weight stays constant.
  • Same pulling speed (approximate).
  • Same block used throughout.
  • Only surface changed.

• Data Recording:

  • Use provided worksheet with table for raw data entry and averaging.
  • Include a sketch of the experiment setup.

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3. Plenary: Data Analysis and Discussion (10 minutes)

• Bring the class together.
• Invite pairs to share their data on which surfaces had the highest and lowest friction force.
• Discuss patterns observed: rougher surfaces (sandpaper) produce higher friction; smooth surfaces produce less friction.
• Introduce how friction can be of practical benefit (car tyres gripping road) or a problem (friction causes wear).
• Ask students to suggest improvements or further variables to test (e.g., weight of block, temperature).

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4. Assessment (5 minutes)

• Quick Quiz: On mini whiteboards or verbal answers
  1. What is friction?
  2. Name two surfaces that increase friction.
  3. Why is it important to keep the weight of the object constant?
  4. How can friction be useful in everyday life?
• Mark answers informally and give immediate feedback.

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Differentiation

• Support:
  • Paired work to share tasks.
  • Sentence starters on worksheets to scaffold explanations.
• Challenge:
  • Introduce idea of coefficient of friction qualitatively.
  • Extend to consider how friction changes if the block’s weight increases.
• SEND:
  • Use larger force meters for easier reading.
  • Provide TA support during practical.

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Health and Safety

• Remind students to handle force meters correctly.
• Clear walkways to avoid trips around experiment area.
• Use goggles if required by local science safety guidelines (though minimal risk).

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Cross-Curricular Links

• Maths: Measurement, averages, graphing results.
• DT (Design Technology): Understanding material properties and practical consequences.
• PSHE: Understanding safety and the real-world application of science to everyday life.

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Homework / Extension Suggestions

• Research and write a short paragraph on an invention that uses friction in a helpful way (e.g., car brakes, shoe soles).
• Design a simple experiment at home to test friction (e.g., sliding objects on kitchen surfaces).

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This lesson plan offers dynamic, hands-on exploration aligned with the national curriculum, fostering scientific enquiry skills while embedding knowledge about forces and friction tailored for a Year 7 set 2 class.