PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A firefighter pushes against a rigid, uniform ladder of length 5.0 m that rests against a frictionless wall. The bottom of the ladder is 3.0 m from the wall on a rough horizontal surface, and the top touches the wall. Treat the wall contact as a smooth point (no friction). The firefighter exerts a horizontal force of 200 N on the ladder at a point 1.0 m above the ground, directed toward the wall.
(1) Calculate the magnitude and sign of the torque produced by the firefighter’s push about the base of the ladder.
(2) Determine whether the push described in part (a) tends to make the ladder slide up or down the wall. Justify your answer using torque considerations.
(3) At what vertical height along the ladder would a horizontal push of the same 200 N produce zero torque about the base? Show your reasoning.