Question

Forces are called coplanar when all of them acting on a body lie in

• A. One Plane
• B. One Point
• C. Different planes
• D. Perpendicular planes

Hint:

Break down the word: Co- (together/same) + Planar (plane) = Same Plane. Similarly, Co- + Linear = Same Line.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
In engineering mechanics, systems of forces are classified based on the spatial relationships of their lines of action.

Step 2: Detailed Explanation:
Let us define the classifications of force systems:
- Coplanar force system: A system of forces is coplanar if the lines of action of all the forces lie within the same two-dimensional plane.
- Concurrent force system: A system of forces is concurrent if the lines of action of all the forces intersect at a single common point.
- Collinear force system: A system of forces is collinear if all forces act along the same straight line of action.
- Non-coplanar force system: A system of forces is non-coplanar (or spatial) if the lines of action of the forces lie in different three-dimensional planes.
Since the prefix "co-" denotes sharing and "planar" refers to a plane, coplanar forces must lie in a single plane.

Step 3: Final Answer:
Forces are called coplanar when they all lie in one plane.