The 12-ft boom AB has a fixed end A. A steel cable is stretched from the free end B of the boom to a point C located on the vertical wall. If the tension in the cable is 500 lb, determine the moment about A of the force exerted by the cable at B. Solution: y A 8 ft 12 ft C i + 4.8 ft → • According to definition, moment about A of the force at B can be expressed as MA = r • The arm 7 = k; • The components of the force: B 1. Direction vector of the force F is 2. Length of the direction vector is 3. Unit vector of the force F is λ = → ft; 4. Thus the tension force on B is resolved to F = + i + i+ 1 + + k; k; k (lb); XF ◆

The 12-ft boom AB has a fixed end A. A steel cable is stretched from the free end B of the boom to a point C located on the vertical wall. If the tension in the cable is 500 lb, determine the moment about A of the force exerted by the cable at B. Solution: y A 8 ft 12 ft C i + 4.8 ft → • According to definition, moment about A of the force at B can be expressed as MA = r • The arm 7 = k; • The components of the force: B 1. Direction vector of the force F is 2. Length of the direction vector is 3. Unit vector of the force F is λ = → ft; 4. Thus the tension force on B is resolved to F = + i + i+ 1 + + k; k; k (lb); XF ◆

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter10: Rotational Motion

Section: Chapter Questions

Problem 9OQ: As shown in Figure OQ10.9, a cord is wrapped onto a cylindrical reel mounted on a fixed,...

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