A uniform ladder rests against a smooth vertical wall and a rough horizontal floor with a coefficient of static friction. If a person climbs up the ladder, which of the following mechanical conditions must be simultaneously satisfied for the ladder to remain in static equilibrium?

💡 Solution & Explanation

For any rigid body to remain in complete static equilibrium, both translational equilibrium requiring zero net external force and rotational equilibrium requiring zero net external torque about any point must be satisfied simultaneously. The frictional force exerted by the floor must act toward the base of the wall to oppose the outward slipping tendency of the ladder base. The center of mass must remain within the base of support for stability. Static friction adjusts automatically up to its maximum limiting value.