Will the Ladder Slip?

Balancing forces and torques

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• A leaning ladder holds if $\mu \ge \frac{1}{2\tan\theta}$ (uniform ladder, smooth wall).
• Shallower angles need more friction; climbers near the top need more still.
• Statics: balance both forces and torques.

Steps

1. A classic of statics
2. Sixty degrees
3. How shallow can it go?
4. The 4-to-1 rule
5. Someone at the top
6. Footing the ladder