Friction force
Answers are for parents and teachers.
1
m = 5 kg, μ = 0.2, g = 10. Sliding friction (N)?
10
2
F = 15 N, N = 50 N. μ?
0.3
3
Give one example each where friction is useful and harmful.
Useful: walking, brakes; harmful: wear of machine parts.
4
Why is sand or salt spread on icy roads?
To increase friction.
5
Why shouldn't you run on slippery surfaces?
Friction is small, so you can slip and fall.