Ladder Against a Wall

A ladder leans against a wall with wheels attached at the top to make it frictionless while the bottom is in contact with four choices of a frictional surface on the floor. The setup allows exploration of the forces and torques acting on the ladder when a weight is hung from any of the seven rungs. By measuring the angle of inclination with a protractor and the force with a spring gauge, the demonstration shows the importance of friction at the base and the conditions for equilibrium, highlighting the concepts of static equilibrium, torque, and frictional forces.