Equilibrium of Forces: JAMB Physics Questions, Answers & Notes

What Equilibrium of Forces covers in the JAMB Physics syllabus

A body is in equilibrium when both the resultant force and the resultant moment on it are zero. The moment (turning effect) of a force = force × perpendicular distance from the pivot, measured in N·m. The principle of moments states that for balance, total clockwise moments = total anticlockwise moments — the key to see-saw and beam problems. The centre of gravity is where a body's whole weight acts; a low centre of gravity and wide base give stability. A couple is two equal, opposite, non-aligned forces causing rotation. The resultant is the single force replacing several; the equilibrant balances them.

For Equilibrium of Forces, JAMB expects you to be able to:

• Apply the conditions for equilibrium of coplanar forces
• Calculate moments and apply the principle of moments
• Understand centre of gravity, stability, couples and the resultant/equilibrant

Key facts & revision notes: Equilibrium of Forces

These are the recurring points our Equilibrium of Forces questions test — revise them until each feels automatic, then practise the questions above to lock them in.

• In equilibrium the resultant (net) force is zero, so there is no acceleration.
• The turning effect of a force about a pivot is its moment (torque).
• Moment = force × perpendicular distance from the pivot.
• Moment = force × distance = 20 × 3 = 60 N·m.
• The principle of moments: total clockwise moments about a point = total anticlockwise moments.
• Such a pair of forces forms a couple, producing pure rotation.
• The centre of gravity is the point where the entire weight of a body seems to act.
• For balance: 2 × 20 = 4 × d, so 40 = 4d, giving d = 10 cm.
• The equilibrant is the single force that balances all others, equal and opposite to the resultant.
• A low centre of gravity (and wide base) gives greater stability.
• Resultant = √(3² + 4²) = √(9 + 16) = √25 = 5 N.
• In stable equilibrium, a slightly displaced body returns to its original position.
• Moment = force × distance, so its unit is the newton metre (N·m).
• A uniform beam has evenly distributed weight, so its centre of gravity is at its midpoint.
• Complete equilibrium requires both zero resultant force and zero resultant moment.
• A freely suspended body settles with its centre of gravity vertically below the suspension point.
• In neutral equilibrium (e.g.
• a ball on a flat table), a displaced body simply stays where it is moved.
• For balance: 30 × 2 = W × 1.5, so 60 = 1.5W, giving W = 40 N.
• The moment (torque) of a couple = one force × the perpendicular distance (arm) between the forces.
• The triangle of forces: three forces in equilibrium form a closed triangle when taken in order.
• Moment = force × distance = 15 × 4 = 60 N·m.
• Moment = 50 × 0.2 = 10 N·m.
• Resultant = √(6² + 8²) = √100 = 10 N.

Worked examples

Three Equilibrium of Forces questions with the answer and a short explanation, so you can see how the topic is set before you practise the full set.

How Equilibrium of Forces is tested in JAMB Physics

Our Equilibrium of Forces bank holds 40 questions (11 easy, 18 medium, 11 hard). JAMB Physics typically returns to Equilibrium of Forces year after year, so steady practice on this topic is high-value revision. Questions are multiple-choice with four options, and at UTME pace you get roughly 40 seconds each — which is why timed practice matters.

How to answer Equilibrium of Forces questions

Work the stem first and predict the answer before you look at the options; then eliminate the ones that contradict the key facts above. Watch for “which is not…”, “all of the above” and “except” style stems, which are where rushed candidates lose easy marks on Equilibrium of Forces. If a calculation or a precise definition is involved, work it from first principles rather than guessing from a half-remembered rule. When two options look right, re-read the stem for the qualifier that separates them — JAMB rarely repeats an option by accident. If you are still unsure, eliminate the two weakest choices to lift your odds, flag the question, and move on; never burn a full minute on one Physics item when the exam gives you about forty seconds each. Then come back to flagged questions with whatever time remains. The single most reliable way to get faster at Equilibrium of Forces is repeated timed practice, so use the button above until the recurring patterns feel automatic.

Common mistakes to avoid in Equilibrium of Forces

The errors that cost marks on Equilibrium of Forces are usually careless rather than conceptual: misreading a negative stem, confusing two similar terms, or rushing a definition you actually know. Candidates also over-rely on “expo” and last-minute cramming instead of understanding the topic — which fails the moment JAMB rephrases a familiar idea. Treat every option as a claim to be checked against the facts above, keep your working tidy for any calculation, and don’t change a considered answer on a hunch. Above all, revise Equilibrium of Forces actively by answering questions, not just by re-reading notes — recall under time is what the exam rewards.

Frequently asked questions

Is Equilibrium of Forces part of the JAMB Physics syllabus?

Yes. Equilibrium of Forces is a recognised topic in the JAMB Physics syllabus, covering apply the conditions for equilibrium of coplanar forces. You should be able to recall its key facts and apply them to multiple-choice questions.

How many Equilibrium of Forces questions can I practise on Belmadeng?

There are 40 original, JAMB-standard Equilibrium of Forces questions in our free bank, each with the correct answer and a worked explanation. You can practise them untimed or as a timed test.

What are the most important points to know about Equilibrium of Forces?

A body is in equilibrium when both the resultant force and the resultant moment on it are zero. The moment (turning effect) of a force = force × perpendicular distance from the pivot, measured in N·m. The principle of moments states that for balance, total clockwise moments = total anticlockwise mom…

How do I answer Equilibrium of Forces questions quickly in JAMB?

Read the stem carefully, eliminate clearly wrong options, and match the remaining choices to the key facts for Equilibrium of Forces. Practising timed Equilibrium of Forces questions builds the speed you need for UTME's pace of about 40 seconds per question.

Are these JAMB Physics Equilibrium of Forces questions past questions or original?

They are original questions written to JAMB (UTME) standard and mapped to the official syllabus — not reproduced past papers. This keeps them legal to use freely while closely mirroring how the real exam tests the topic.

Where can I practise Equilibrium of Forces questions free without signing up?

Right here — tap “Start Equilibrium of Forces practice” on this page to begin instantly. Belmadeng's CBT practice is completely free and needs no sign-up, download or subscription.

About these questions: original, JAMB-standard items written from the official UTME Physics syllabus (last reviewed 2026-09-18). Belmadeng is an independent study platform and is not affiliated with JAMB. Spotted an error? Use the report link.