Concepts

Torque, friction

Overview

A ladder leans against a wall, on the verge of slipping. A hooked mass can be moved up the rungs of the ladder until the ladder slips.

Details

Equipment

• [1] Model ladder
  
• [1] Wall
• [1] Wooden plank
  
• [4] C-clamp
• [1] 1 kg mass
  
• [1] S-hook
• [1] Metre stick

Classroom Assembly

1. Clamp the wall to a table.
2. Clamp the plank next to it.
3. Lean the ladder against the wall.
4. Place the metre stick next to the plank and the ladder for scale.
   

Script

1. Find the angle at which the ladder starts to slip.
2. Hang the mass at various rungs of the ladder, going up from the lowest rung.
3. When the mass reaches or passes the middle of the ladder, it should slip.
   

Additional Resources