You will learn
- Define friction.
- Test surfaces.
- Explain heat from friction.
- Increase or reduce friction.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Friction opposes motion.
- Rough surfaces give more friction.
- Friction makes heat.
- Lubricants reduce friction.
Words to know
a force that slows sliding surfaces
a slippery substance that reduces friction
the friction between shoe and floor
the pattern on a tyre or shoe
1. Discover: The slippery floor
After mopping, the hall floor is slippery. Adwoa slides in her socks, but in her school shoes she walks safely. “Shoe treads grip the floor,” says the caretaker. “Wet floors have less friction.”
Think: How can we make floors safer?
2. Understand: Friction
Idea 1: Resists motion
Friction acts where surfaces rub. It always opposes motion and turns kinetic energy into heat. Rub your hands to feel it.
Idea 2: Surfaces
Rough surfaces give more friction than smooth ones. Heavier objects pressed harder together also have more friction. Tyres have tread for grip.
Idea 3: Use and reduce
We increase friction with grips and treads. We reduce it with oil, grease or other lubricants, smooth surfaces and wheels.
3. Worked examples
Example 1 (I show you): Predict
Rough floor.
- More friction.
- Harder to slide.
- Grip.
Answer: More friction.
Example 2 (We do it together): Predict
Oiled hinge.
- Less friction.
- Smooth.
- Quiet.
Answer: Less friction.
Example 3 (You try): Explain
Warm hands.
Show the steps and answer
- Rub.
- Heat.
- Energy.
Answer: Friction makes heat.
Did you know?
Spacecraft re-entering the atmosphere reach over 1,500 °C partly because of friction with the air.
Why this matters
Understanding friction helps us design safe shoes, brakes and machines.
4. Explore: Friction lab
Pull a block across sandpaper, card, cloth and a smooth tray with a spring balance and compare forces.
- Attach the balance.
- Pull steadily.
- Read newtons.
- Repeat for each surface.
Think about it: what did you notice?
What did you notice? Sandpaper needed the most force.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- ___ is a force that slows sliding surfaces.
- A ___ reduces friction.
- ___ is friction between shoe and floor.
- ___ is a pattern on a tyre.
Guided practice
Question 1. What is friction?
Opposes motion.
Question 2. What is a lubricant?
Slippery.
Question 3. What is grip?
Hold.
Independent practice
Level 1: Start
- What is friction?
- What is a lubricant?
- What is grip?
- What is tread?
- What does friction make?
Level 2: Grow
- Why tread?
- Why oil?
- Why rough surface?
Level 3: Stretch
- Run the test.
- Graph.
- Explain.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Explain why shoes have treads.
Show a sample answer
Use grip.
Another one. Tell a family member one thing from this lesson. Use the words you learned.
Show a sample answer
A clear sentence that uses at least one word from Words to know.
7. Common mistakes
Fix: Useful too.
Fix: Some.
8. Lesson summary and revision card
- I can define friction.
- I can test surfaces.
- I can explain heat from friction.
- I can increase or reduce friction.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- Friction opposes motion.
- Rough surfaces give more friction.
- Friction makes heat.
- Lubricants reduce friction.
11. Next lesson
Next lesson: Balanced and unbalanced forces. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- Define friction and lubricant. [2 marks]
- Describe a friction test. [4 marks]
- Give a use of friction and a way to reduce it. [2 marks]
- Safety rule. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 1 each
- Surfaces [1]; same block [1]; balance [1]; compare [1]
- 1 each
- Any [1]; reason [1]
Score guide: 9 to 10 = secure. 6 to 8 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- What is friction?
- What is a lubricant?
- What is grip?
- What is tread?
- What does friction make?
- Why tread?
- Why oil?
- Why rough surface?
- Run the test.
- Graph.
Homework
Rub two surfaces and describe the friction.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What is friction? | Opposes motion. | 1 |
| 2. What is a lubricant? | Slippery. | 1 |
| 3. What is grip? | Hold. | 1 |
| 4. What is tread? | Pattern. | 1 |
| 5. What does friction make? | Heat. | 1 |
| 6. Why tread? | Grip. | 1 |
| 7. Why oil? | Less friction. | 1 |
| 8. Why rough surface? | More friction. | 1 |
| 9. Run the test. | Table. | 1 |
| 10. Graph. | Bar chart. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Opposes motion.; 2 Slippery.; 3 Hold.; 4 Pattern.; 5 Heat.. Level 2: 1 Grip.; 2 Less friction.; 3 More friction.. Level 3: 1 Table.; 2 Bar chart.; 3 Sentence..
Quiz answers: 1 B, 2 C, 3 A, 4 B, 5 C, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 B, Challenge 2 C.
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Define friction | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Test surfaces | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Explain heat from friction | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Increase or reduce friction | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: “Friction is always bad.” Useful too.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Explain friction.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child tests friction. You do not need to be an expert to help.
- Slide objects on surfaces.
- Ask “Which is slippery?”
- Mind wet floors.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: define friction; test surfaces; explain heat from friction; increase or reduce friction.
Prerequisite knowledge. Grade 4 ideas: pushes and pulls, gravity, friction, simple machines and strength and stability of structures.
Materials. Block, balance, surfaces. Low-resource options: use chalk or charcoal on a board or wall, drawings in the sand, and objects from the classroom instead of printed materials.
Preparation. Gather surfaces.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Rub hands together and ask, “What do you feel?”
Explanation (10 min). Teach friction.
Guided activity (10 min). Learners test.
Independent activity (10 min). Learners explain.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. More or less friction? Why?
Teacher explanation notes. Start with real objects and safe, hands-on observation. Then talk about what was seen, then draw and write. Always say “how do you know?”. Keep to the safety notes, and use local, safe materials.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and pictures, short sentences and a partner. Let learners point, show or draw instead of writing. Extension. Ask learners to find a new example at home and explain how they know.
Formative assessment. Listen to learners read and explain, ask “how do you know?”, and check the independent work.
Misconceptions. “Friction is always bad.” Useful too.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz, the 10-mark exam practice and the worksheet on this page. All answers and marking guides are in the answer sections above. Re-check every answer before use.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Explain friction. Enrichment. Look for one new example near your home or school, draw it and explain it to someone. Homework. See above.
Teacher reflection. After teaching, record: which ideas learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points: Next Generation Science Standards, Cambridge Primary Science and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Research used to shape this lesson. Courseversity Science curriculum, Grade 5 Unit 6, topic 4; Next Generation Science Standards, forces and interactions; Cambridge Primary Science Stage 5, physics: forces and motion; IB Primary Years Programme, how the world works. These sources informed the lesson.