Topic 4 ( RESULTANT OF FORCE SYSTEMS )

Question 1

Keywords: Simplify, single force, same effect
Definition: A single force that represents the combined effect of multiple forces acting on a rigid body

Answer 1

Resultant Force

Question 2

Keywords: Common point, head-to-tail, magnitude, angle
Definition: Forces acting at a single point. The resultant is found using the head-to-tail method to determine its magnitude and direction.

Answer 2

Concurrent Forces

Question 3

Keywords: Same/opposite direction, sum, moments
Definition: Forces that are parallel to each other. The resultant is their algebraic sum, and its location is determined using the Principle of Moments.

Answer 3

Parallel Forces

Question 4

Keywords: Non-concurrent, non-parallel, combined
Definition: A mix of forces that are not all at a common point or parallel. Includes couples and requires vector resolution to find the resultant

Answer 4

General Force Systems

Question 5

Keywords: Force, moment, equivalent
Definition: A combination of a force and a couple (moment) that produces the same external effect on a rigid body.

Answer 5

Force-Couple System

Question 6

Keywords: Vector addition, triangle, direction
Definition: A geometric method to find the resultant of concurrent forces by aligning the tail of one vector to the head of another.

Answer 6

Head-to-Tail Method

Question 7

Keywords: Moments, balance, equilibrium
Definition: States that the moment of a resultant force about a point equals the sum of the moments of individual forces about the same point.

Answer 7

Principle of Moments (Varignon’s Theorem)

Question 8

Forces that act along the same line; resultant is the algebraic sum.

Answer 8

Collinear Forces

Question 9

Forces lying in the same plane; resultant found using vector resolution or graphical methods.

Answer 9

Coplanar Forces

Question 10

Forces that don’t meet at a single point; resultant determined using moments and vector components.

Answer 10

Non-Concurrent Forces

Question 11

is a simplified representation of a system of forces acting on a rigid body. It combines:
Equivalent representation of a force and a couple (moment) acting on a rigid body.

Answer 11

Force-Couple System

Question 12

A state where the resultant force and resultant moment are both zero (important when analyzing force systems).

Answer 12

Equilibrium

Question 13

Another graphical method to determine the resultant of two forces.

Answer 13

Parallelogram Method

Question 14

The size of the resultant force, often found using the Pythagorean theorem or trigonometry.

Answer 14

Resultant Magnitude