S2.5.3 For the adult
Friction
Why does a sliding thing slow down and stop?
What this chapter teaches
Friction is a force between two surfaces that rub or try to slide. It acts against the slide, and rough surfaces give more of it. Friction helps us walk and hold things, and it slows things down. A thing stops because friction slows it, not because its push runs out.
Three questions to ask
There is no one right wording. Listen for the idea.
- Why does a bottle top slide further on a smooth floor than on sand?
- How does friction help you when you walk?
- What slows a ball that rolls over grass?
After the chapter, the learner can
- Compare how far an object slides on smooth and rough surfaces
- Explain how friction helps us walk and slows things down
What they copy into their notebook
Friction is a force between two surfaces that rub. It acts against the slide. Rough surfaces give more friction than smooth ones. Friction helps us walk and hold things. It also slows things down.