A painter climbs a ladder leaning against a smoothwall. At a certain height, the ladder is on the verge of slipping.(a) Explain why the force exerted by the vertical wall on theladder is horizontal. (b) If the ladder of length L leans at anangle u with the horizontal, what is the lever arm for this horizontalforce with the axis of rotation taken at the base of theladder? (c) If the ladder is uniform, what is the lever arm forthe force of gravity acting on the ladder? (d) Let the mass ofthe painter be 80 kg, L = 4.0 m, the ladder’s mass be 30 kg,θ = 53°, and the coefficient of friction between ground andladder be 0.45. Find the maximum distance the painter canclimb up the ladder.

A painter climbs a ladder leaning against a smoothwall. At a certain height, the ladder is on the verge of slipping.(a) Explain why the force exerted by the vertical wall on theladder is horizontal. (b) If the ladder of length L leans at anangle u with the horizontal, what is the lever arm for this horizontalforce with the axis of rotation taken at the base of theladder? (c) If the ladder is uniform, what is the lever arm forthe force of gravity acting on the ladder? (d) Let the mass ofthe painter be 80 kg, L = 4.0 m, the ladder’s mass be 30 kg,θ = 53°, and the coefficient of friction between ground andladder be 0.45. Find the maximum distance the painter canclimb up the ladder.

Glencoe Physics: Principles and Problems, Student Edition

1st Edition

ISBN:9780078807213

Author:Paul W. Zitzewitz

Publisher:Paul W. Zitzewitz

Chapter8: Rotational Motion

Section: Chapter Questions

Problem 69A

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