Reducing and Increasing Friction

Active learning works well for this topic because friction is a tangible force students can feel and see. Hands-on stations and design tasks let them test ideas immediately, which builds stronger understanding than abstract explanations alone.

• Year 5
• Science
• 4 activities
• 30 min–45 min

Learning Objectives

1. Explain how lubricants reduce friction between moving parts in simple machines.
2. Compare the effectiveness of different materials (e.g., oil, wax, dry) in reducing friction on a ramp.
3. Design and construct a simple device that increases friction for a specific purpose, such as improving grip.
4. Analyze the trade-offs between increasing and decreasing friction in everyday scenarios.

Stations Rotation

⏱ 45 min·Small Groups

Stations Rotation: Friction Tweakers

Prepare four stations with ramps: test plain wood, oiled wood, sandpaper, and rubber treads. Students release identical toy cars from the top, time descents with stopwatches, and note which surface speeds up or slows motion most. Groups rotate, pooling data for class graphs.

Prepare & details

Explain how lubricants reduce friction in machines.

Facilitation Tip: During Station Rotation: Friction Tweakers, set a timer for each station and circulate to ask guiding questions like, 'What do you notice about the force needed when the surface is oiled?'

Setup: Tables/desks arranged in 4-6 distinct stations around room

Materials: Station instruction cards, Different materials per station, Rotation timer

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 35 min·Pairs

Design Challenge: Grip Enhancers

Pairs identify a problem like wet floors, then prototype shoe soles using card, glue, and textures like string or sand. Test on soapy trays by timing walks or slides. Iterate based on results and peer feedback before presenting best designs.

Prepare & details

Compare situations where we want to increase friction versus decrease it.

Facilitation Tip: For Design Challenge: Grip Enhancers, provide a clear success criterion such as 'Your tread pattern must prevent a 30-degree incline block from sliding,' to focus student design work.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 30 min·Individual

Ramp Investigation: Lubricant Effects

Whole class sets up identical ramps. Individuals predict, then apply cooking oil or soap to surfaces and race marbles, measuring distances slid. Record before-and-after times in tables, discussing why changes occur.

Prepare & details

Design a solution to either increase or decrease friction for a specific problem.

Facilitation Tip: In Ramp Investigation: Lubricant Effects, ask students to measure the distance a block travels and record it in a shared class table to encourage data-driven comparisons.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 40 min·Small Groups

Surface Hunt: Real-World Friction

Small groups survey school areas for high and low friction spots, like grass versus tiles. Test with dragged objects, rate friction levels, and propose improvements such as adding gravel paths. Share findings in a class map.

Prepare & details

Explain how lubricants reduce friction in machines.

Facilitation Tip: During Surface Hunt: Real-World Friction, assign pairs to photograph and label at least three examples of friction in action, then share findings with the class.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Teaching This Topic

Teachers should start with students’ prior experiences, such as walking on slippery ice or gripping sports shoes, to anchor new concepts. Avoid over-simplifying by acknowledging that friction is always present, even if reduced. Research shows students learn best when they test predictions, record data, and explain discrepancies, so prioritize time for these steps over rushing to conclusions.

What to Expect

Students should explain how friction changes with surfaces and lubricants, compare scenarios for high or low friction, and design effective solutions. They should use evidence from investigations to support their reasoning and adjust their designs based on results.

Watch Out for These Misconceptions

Common Misconception

During Station Rotation: Friction Tweakers, watch for students who assume only rough surfaces create friction. Redirect them to compare polished wood with oiled wood, noting the difference in block movement.

What to Teach Instead

During Station Rotation: Friction Tweakers, have students record the force needed to move a block on different surfaces. Ask, 'What do the numbers tell us about smooth surfaces?' to guide them to recognize friction still exists but is reduced.

Common Misconception

During Ramp Investigation: Lubricant Effects, watch for students who think oil removes all friction. Redirect them to observe that the block still slows down, just less than on a dry ramp.

What to Teach Instead

During Ramp Investigation: Lubricant Effects, ask students to compare the distance a block travels on dry, wet, and oiled ramps. Challenge them to explain why the block never travels infinitely far, fostering understanding of partial friction reduction.

Common Misconception

During Design Challenge: Grip Enhancers, watch for students who argue high friction is always better for safety. Redirect them to consider trade-offs, such as how too much grip can make movement difficult.

What to Teach Instead

During Design Challenge: Grip Enhancers, after testing tread patterns on inclines, ask groups to discuss scenarios where too much friction might be a problem. Guide them to refine designs for specific contexts, like icy paths versus gym floors.

Assessment Ideas

Exit Ticket

After Station Rotation: Friction Tweakers, give students two scenarios: 1) a bicycle chain needing to move smoothly, and 2) a steep slide needing more grip. Ask them to write one sentence for each scenario explaining whether friction should be increased or decreased and name one method to achieve this.

Discussion Prompt

After Design Challenge: Grip Enhancers, pose the question: 'Imagine you are designing a new type of skateboard wheel. What would be the advantages and disadvantages of making the wheels very smooth versus very rough?' Facilitate a class discussion comparing the impact of friction in this context.

Quick Check

During Surface Hunt: Real-World Friction, show students images of different objects (e.g., ice skates, car tires, sandpaper, a greased pan). Ask them to hold up a green card if the object is designed to reduce friction and a red card if it is designed to increase friction. Follow up by asking them to justify their choice for one or two examples.

Extensions & Scaffolding

• Challenge early finishers to design a shoe sole that balances grip on dry pavement and wet grass, testing their prototype and refining it based on results.
• Scaffolding for struggling students: Provide sentence starters like 'When the surface is smoother, the block slides farther because...' to help them articulate observations during ramp tests.
• Deeper exploration: Ask pairs to research and present on how engineers use friction in bridge construction or sports equipment, linking their classroom findings to real-world applications.

Key Vocabulary

Friction	A force that opposes motion when two surfaces rub against each other. It can slow things down.
Lubricant	A substance, like oil or grease, that is put between moving surfaces to make them slide more easily and reduce friction.
Tread	A pattern on the surface of tires or shoes designed to increase grip by providing more points of contact and channeling away water or debris.
Surface Area	The total area of the outside surfaces of an object. Different surface areas can affect how much friction occurs.