Center of gravity in engineering mechanics\n\nThe point through which the entire weight of a body may be considered to act, irrespective of its orientation, is known as the:

Introduction / Context:
Designers and analysts must know where the weight of a body can be assumed to act to simplify calculations of support reactions, stability, and tipping. This conceptual question distinguishes multiple “centres” used in mechanics.

Given Data / Assumptions:

• Weight is a force equal to mass * g acting downward toward Earth's centre.
• We assume a uniform gravitational field over the body's extent (a good approximation for most engineering applications).

Concept / Approach:
The centre of gravity (CG) is the point where the resultant weight of the body acts. For a uniform gravitational field, the centre of gravity coincides with the centre of mass, but the term CG emphasizes the action point of weight (a force).

Step-by-Step Solution:

Verification / Alternative check:
In a non-uniform gravitational field, CG and centre of mass may differ slightly. In standard terrestrial problems, they effectively coincide, validating the selection.

Why Other Options Are Wrong:

• Moment of inertia: A property measuring resistance to angular acceleration, not a point.
• Centre of percussion: A specific point on a swinging body where impact causes no reaction at the pivot.
• Centre of mass: Mass centroid; close in meaning but the question explicitly stresses weight action.
• Barycentre: General term for mass centroid of a system; used in orbital mechanics for two-body systems.

Common Pitfalls:
Using centre of mass and centre of gravity interchangeably without noting the emphasis on force (weight) in the definition.

Final Answer:
centre of gravity