I can use force and moment equilibrium to calculate unknown support reactions.
POE Unit 2 • Lesson 2.6
Static Equilibrium
Focus question: What conditions must be satisfied for a loaded structure to remain at rest?
Mission Briefing
Today’s Plan
A focused sequence that builds toward the aerospace payload support structure challenge.
Opening promptConcept modelGuided analysisInteractive practiceEvidence checkExit ticket
Lesson Targets
What You Will Be Able to Do
Equilibrium solution
The support reactions satisfy both force balance and moment balance with correct signs and units.
Activity Flow
How the Lesson Moves
Each step builds the structural reasoning needed for the lesson deliverable.
1. Model the structure
Create a free body diagram with known loads and unknown reactions.
2. Apply moment equilibrium
Choose a pivot that reduces the number of unknowns.
3. Verify force balance
Use the calculated reactions to confirm the net force is zero.
Lesson Interactive
Calculate the Support Reactions
A simply supported beam carries a 120 N centered load. Determine the vertical reaction at each support.
Loaded Beam
The geometry and loading are symmetric. The beam is at rest.
Reaction Forces
Use symmetry or moment equilibrium, then verify that the vertical force sum equals zero.
Today’s Work
Main Deliverable
Support-Reaction Solution
Solve one statically determinate support problem.
- Show the free body diagram and equations for force and moment equilibrium.
- Report the support reactions with units and verify both equilibrium conditions.
Exit Ticket
Mission Debrief
State one structural idea from today in your own words.
Name one calculation, measurement, diagram, or observation that could support a design decision.
Identify one question or risk to carry into the next structural lesson.
Resources
Lesson Resources
Lesson 2.6 PowerPoint
Use the presentation to review the lesson concepts, examples, and activity directions.
Principles of Engineering
Return to the POE course hub for units, resources, certifications, and current course information.
Aerospace Payload Support Structure
Use this unit project context when connecting analysis, material decisions, prototype testing, and final design-review evidence.