Question: What is the condition for a rigid body to be in static equilibrium?

Options:

1. The sum of all forces acting on the body is zero.
2. The sum of all moments about any point is zero.
3. Both the sum of forces and the sum of moments are zero.
4. The body must be at rest.

Correct Answer: Both the sum of forces and the sum of moments are zero.

Solution:

For a rigid body to be in static equilibrium, both the sum of all forces and the sum of all moments acting on the body must be zero.