Lesson: Equilibrium of a Rigid Body under Parallel Forces Mathematics

In this lesson, we will learn how to solve problems about the equilibrium of a body under the effect of parallel coplanar forces.

Lesson Plan

Objectives

Students will be able to

recognize when a body is in equilibrium under parallel forces,
sketch a force diagram for a body in equilibrium under parallel forces,
solve static problems involving parallel forces by finding resultant forces and taking moments.

Prerequisites

Students should already be familiar with

moments,
how to find the resultant of parallel forces,
uniform rods.

Lesson Video

Lesson Explainer

Sample Question Videos

04:55
09:49
07:31

Lesson Worksheet

Q1:

A uniform rod having a weight of 64 N and a length of 168 cm is resting horizontally on two identical supports at its ends. A weight of magnitude 56 N is suspended at a point on the rod that is cm away from . If the magnitude of the reaction at is double that at , determine the value of .

Q2:

A uniform rod having a weight of 35 N is resting horizontally on two supports and at its ends, where the distance between the supports is 48 cm. If a weight of magnitude 24 N is suspended at a point that is 38 cm away from , determine the reactions of the two supports and .

Q3:

A non-uniform rod having a weight of 40 N and a length of 80 cm is suspended vertically from its midpoint by a light string, and it becomes in equilibrium in a horizontal position when a weight of magnitude 29 N is suspended from its end . Determine the distance between the point at which the weight of the rod is acting and end . After removing the weight at , determine the magnitude of the vertical force that would be needed to keep the rod in equilibrium in a horizontal position when it acts at end .