Meriam, Kraige & Bolton — Equilibrium of Rigid Bodies: Problem 4_73

⚡ Mecademy AIENG정역학 · ch4  Problem Statement For a gripping force of 20 lb, determine the normal force exerted on the round stock by each jaw. Also, determine the magnitude of the force supported by the pin at . Problem 4/73 (a) Normal force exerted on the round stock ● Calculation Process 1. Present Final Formula: We consider the equilibrium of one member of the pliers (e.g., the member consisting of the lower handle and the upper jaw). Taking the sum of moments about the pivot pin : where is the gripping force, is the horizontal moment arm of the hand force, is the normal force on the stock, and is the perpendicular distance to the line of action of . 2. Substitute Values: From the diagram, the gripping force and its horizontal distance from is . The normal force acts at a distance along the jaw axis. Since is perpendicular to the jaw axis, its moment arm is exactly . 3. Partial Operations: 4. Final Calculation: ● Final Conclusion: The normal force exerted on the round stock is . (b) Magnitude of the force supported by the pin at N O N O M = ∑ O 0⟹F⋅L−N⋅d=0 FLN d N F=20 lb OL=16 inNd= 4 inN 4 in 20 lb⋅16 in−N⋅4 in=0 320 lb⋅in=4N in N= = 4 320 80 lb N80 lb O ● Calculation Process 1. Present Final Formula: We analyze the force equilibrium of the same member in the and directions. Let the handle be along the horizontal () axis. The jaw is at an angle to the handle. The normal force is perpendicular to the jaw, so it acts at an angle of with the horizontal. 2. Substitute Value