Rule of moments and dynamics of circular motion
Answers are for parents and teachers.
1
Lever: F₁ = 40 N, l₁ = 0.5 m; F₂ = 25 N. At what l₂ (m) is it balanced? (give a decimal)
0.8
2
A block and tackle with 6 ropes lifts a 1200 N load (ideal). What force is needed (N)?
200
3
A 1 kg ball moves on a circle of R = 0.5 m with ω = 4 rad/s. What is the centripetal force (N)?
8
4
R = 40 m, μ = 0.4, g = 10. What is the greatest speed on the turn (m/s)? (√(μgR), to 0.1)
12.6
5
Why does a motorcyclist lean inward on a turn?
So that the resultant of friction and reaction points toward the centre and the moments balance.