FE Civil Practice Question Solution included after investigation
CASE E-042 Β· FE

The Beam Reactions That Refused to Split 50-50

The total load was 28 kN, but the support reactions were not 14 kN each.

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Case E-042 engineering failure visual
HOW THIS WORKS

Think like
a real engineer.

Follow the investigation process used in the field β€” in five guided steps.

1

Inspect

Review the problem, diagram, and evidence.

2

Commit

Choose your hypothesis.

3

Prove

Run calculations and test your idea.

4

Fix

Select and validate a safe correction.

5

Sign Off

See the full debrief and key takeaways.

Case Brief

SAME PRINCIPLES. HIGHER STANDARDS.
PROBLEM STATEMENT

A simply supported 6 m beam has a pin at A and a roller at B. An 8 kN downward load acts 1 m from A, and a 20 kN downward load acts 4 m from A. A quick check assigns 14 kN to each support because the total load is 28 kN. Calculate the actual reactions and identify why the equal split is incorrect.

Statics Civil Design Verification Root Cause Analysis Safe Correction
E-042
INVESTIGATION WORKSPACE WORK THROUGH THE CASE β€” YOUR CHOICES MATTER.
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DEBRIEF (LOCKED)

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Find the root cause, confirm the fix, and see how this connects to the exam.

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CASE CLOSED Β· ENGINEERING VERDICT

What actually failed β€” and what should change.

What failed

The reaction split was based only on total force.

What was missed

The loads create unequal moments about the supports.

Corrected model

Use Ξ£F=0 and Ξ£M=0 on the complete beam free-body diagram.

QUICK ANSWER

For a 6 m simply supported beam with 8 kN at 1 m and 20 kN at 4 m from A, moment equilibrium about A gives RB(6)=8(1)+20(4)=88, so RBβ‰ˆ14.67 kN. Vertical equilibrium then gives RAβ‰ˆ13.33 kN.

ENGINEERING TAKEAWAY

Use both force equilibrium and moment equilibrium. Load location controls the reaction distribution.

CASE QUESTIONS

Questions this case should settle.

Do simply supported beam reactions always split equally?

No. Equal reactions occur only for appropriate symmetric loading.

Why take moments about a support?

It removes that support reaction from the moment equation and lets the other reaction be solved directly.

NEXT FE PRACTICE QUESTION

The Truss Diagonal That Carried More Than the Support Reaction

Statics Β· 5–10 min

Continue Practice β†’
WHAT YOU’LL LEARN

Real failures. Lasting skills.

Each case is designed to build the judgment, analysis, and confidence you need for engineering exams β€” and beyond.

  • Apply core engineering concepts to real-world problems
  • Practice structured troubleshooting and analysis
  • Strengthen exam-ready thinking through realistic scenarios
COMMON QUESTIONS
Do I need prior knowledge to use these cases?

Basic subject familiarity helps, but every case is designed to teach through the investigation itself.

How long does a case take?

Most cases are designed for a focused 5–10 minute investigation.

Are the cases aligned with engineering exams?

Each case is mapped to a verified exam, subject, topic, and misconception before publication.

What happens after I complete a case?

The sealed debrief unlocks with the root cause, corrected reasoning, fix, and takeaway.