Warning: insufficient friction

Friction seems like a nuisance. The inventor of the wheel was surely the Einstein of his age. But without friction forces, couldn't walk or drive: we would travel in a straight line at constant speed -- and fall down.

Main pages in this section	Estimated time required
Exploring friction	30 minutes
More about friction	30 minutes
Science content: Friction	30 minutes
Discussion of the unit on friction	30 minutes

Materials needed for this section

• Force scale*
• board with hook *
• track sections *
• steel balls *
• round pencils *

Supplementary material:
Why study friction?
More about friction

Next section:Vibration