Friction: Forces That Slow Us Down

Year 4 Science Exploring how friction affects movement in our daily lives

What Do You Think?

Why do you think a ball rolling on grass stops faster than a ball rolling on a smooth floor? Think about what might be causing the difference...

What is Friction?

Friction is a force that happens when two surfaces rub against each other It always works against movement Friction tries to slow things down or stop them moving We can feel friction when we rub our hands together

Smooth vs Rough Surfaces

{"left":"Ice, glass, polished wood, wet surfaces","right":"Sandpaper, carpet, grass, tree bark"}

Friction Investigation

Try sliding different objects across your desk Test: rubber, wooden ruler, plastic toy Which slides furthest? Which stops quickest? What do you notice about the surfaces?

Friction in Everyday Life

Walking - friction between shoes and ground stops us slipping Bike brakes - friction stops the wheels turning Writing - friction between pencil and paper makes marks Car tyres - friction helps cars grip the road and stop safely

Think About This!

What would happen if there was no friction at all? How would you walk? How would cars stop? Could you pick up objects?

How Friction Helps and Hinders

Reducing Friction Experiment

Slide a book across your desk Now put pencils under the book like rollers Slide it again - what happens? Try adding soap or oil to make surfaces slippery How do these changes affect movement?

What We've Learned About Friction

Friction is a force that opposes movement Rough surfaces create more friction than smooth ones Friction can be helpful (walking, braking) or unhelpful (wearing out objects) We can increase or decrease friction depending on what we need Friction is everywhere in our daily lives!