Question 9
Equilibrium of ForcesI. All the three forces must be concurrent
II. The upward force is equal to the downward force
III. The algebraic sum of the moment about any point must be zero.
Which of the above conditions must hold for a body acted upon by a system of three coplanar forces in equilibrium?
- A.I and II only
- B.I and III only
- C.II and III only
- D.I,II and III
Show the answer and explanation
Answer: D (I,II and III)
Explanation
Three non-parallel forces in equilibrium must meet at one point, the forces must balance (upward = downward, left = right), and the total moment about any point must be zero. All three statements hold.