S2.5.4 For the adult
More friction or less
How can we get less friction, or more?
What this chapter teaches
Oil, water and wheels give less friction. Rough rubber, sand and grooves give more grip, most of all on wet or muddy ground. Friction is not always bad. We need it to hold, walk and stop, so sometimes we want less and sometimes more.
Three questions to ask
There is no one right wording. Listen for the idea.
- Where would you want less friction, and how would you get it?
- Why do shoes for muddy ground have grooves?
- When do you want more friction?
After the chapter, the learner can
- Give ways to reduce friction, such as oil, water or wheels
- Explain why shoe soles and tyres have grooves
What they copy into their notebook
Oil, water and wheels give less friction. Rough rubber and sand give more grip. On wet or muddy ground, grooves help shoes and tyres grip. Water and mud go into the grooves. The rubber touches the ground.