What fundamental condition must be satisfied for a system of forces to be in static equilibrium_____________________?
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Answer: C. both A. and B. above
Explanation
A general three-dimensional force system requires forces to be coplanar and concurrent to satisfy static equilibrium conditions easily. Static equilibrium demands that both the vector sum of all forces and the sum of all moments equal zero simultaneously. When forces share a single plane and meet at one common point, moment equations are automatically satisfied without complex calculations. Static equilibrium is the fundamental branch of mechanics analyzing stationary structures where net forces and moments equal zero. Coplanar force systems operate entirely within a single two-dimensional plane, simplifying vector resolution and equilibrium analysis. Concurrent forces pass through a single intersecting point, eliminating rotational moment arms about that specific spatial coordinate origin.
Forces being merely coplanar is insufficient for equilibrium unless their lines of action also meet or balance rotational moments. Forces meeting at one point alone do not guarantee equilibrium unless their vector sum also equals zero in all directions. Requiring all forces to be equal is completely incorrect because equilibrium only demands that opposing vector forces balance each other.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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