Mechanics for NEET 2025: Laws of Motion, Work, Energy & Power in One Shot

Mechanics is the foundation of NEET Physics. Nearly 25–30% of the Physics section in NEET comes directly from Mechanics-related chapters. Topics like Laws of Motion, Work, Energy, Power, and Motion in 1D/2D not only hold high weightage but also support understanding in other areas like Rotational Motion, Gravitation, and even Thermodynamics.

What makes Mechanics a game-changer is that its questions are application-driven and formula-based. If you’ve built conceptual clarity and practiced well, it becomes one of the most scoring areas of NEET Physics.

In this blog, we’ll cover:

Key concepts from Laws of Motion, Work, Energy & Power
Important formulas for last-minute revision
Previous year NEET questions
Practice MCQs to test your understanding
One-shot strategy tips to master Mechanics

Let’s begin with how and why Mechanics dominates the NEET Physics paper.

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Mechanics in NEET: Weightage & Relevance

Mechanics consistently contributes 10–12 questions in the NEET Physics section—making it the highest weightage cluster in the Physics syllabus.

Chapters Under Mechanics:

Laws of Motion
Work, Energy & Power
Motion in a Straight Line & Plane
System of Particles & Rigid Body
Gravitation
Units & Dimensions (closely related)

These topics appear in NEET every single year and cover both theoretical and numerical MCQs. Many students avoid them due to conceptual difficulty, but with the right breakdown and free-body diagram (FBD) practice, they can become your strongest area.

Tip: Focus on mastering 6–8 high-frequency formulas and applying them to 100+ MCQs. That alone will prepare you for 80% of questions from Mechanics.

Laws of Motion: Concepts & Applications

Newton’s Laws of Motion

First Law (Law of Inertia):

A body remains at rest or in uniform motion unless acted upon by an external force.
📌 Example: A person in a car lurches forward when the brakes are suddenly applied.

Second Law:

F = ma → The force on a body equals its mass multiplied by its acceleration.
📌 Example: A heavier object requires more force to achieve the same acceleration as a lighter one.

Third Law:

Every action has an equal and opposite reaction.
📌 Example: Walking forward involves pushing the ground backward.

Free-Body Diagrams (FBDs):

Drawing all the forces acting on an object helps solve 90% of NEET force-based questions. FBDs are essential for problems involving tension, normal force, friction, or pulleys.

Common NEET Question Types

Inclined Planes:
Use components of weight:
- Along plane: mgsin⁡θmg sinθmgsinθ
- Perpendicular: mgcos⁡θmg cosθmgcosθ
Pulley Systems:
Analyze using constraint relations and assume tension to be the same in the string unless there’s friction or multiple pulleys.
Friction Problems:
- Static friction: $boldsymbol{f_s leq mu_s N}$
- Kinetic friction: $boldsymbol{f_k = mu_k N}$

Most NEET MCQs are based on block-pulley setups, body on inclined plane, or objects in motion under multiple forces.

Quick Formula Box

Concept	Formula
Newton’s 2nd Law	$boldsymbol{F = ma}$
Normal Force (incline)	$boldsymbol{N = mg cos theta}$
Frictional Force	$boldsymbol{f = mu N}$
Tension in Pulley (basic)	$boldsymbol{T = ma}$ or variations with system

Work, Energy & Power: Must-Know Concepts

Work Done by a Force

Work:
$boldsymbol{text{Work} = F cdot d cdot cos theta}$

Angle Interpretations:

If angle between force and displacement is $boldsymbol{0^circ}$ → Positive work
If angle is $boldsymbol{90^circ}$ → Zero work
If angle is $boldsymbol{180^circ}$ → Negative work (e.g., friction)

NEET Link: Questions frequently ask about signs of work or calculate work done by variable forces.

Conservative Forces: Store energy (e.g., gravity, spring)
Non-Conservative Forces: Dissipate energy (e.g., friction)

Energy & Its Forms

Kinetic Energy (KE): $boldsymbol{text{KE} = frac{1}{2}mv^2}$
Potential Energy (PE): $boldsymbol{text{PE} = mgh}$
Mechanical Energy = KE + PE

Law of Conservation of Energy: In a closed system with no non-conservative forces, total mechanical energy remains constant.

NEET Application: Energy conservation is commonly tested in vertical motion, projectile, pendulum, and sliding blocks.

Power and Efficiency

Power:
$boldsymbol{text{Power} = frac{text{Work}}{text{Time}}}$
Instantaneous Power:
$boldsymbol{P = F cdot v}$
Commercial Unit of Energy:
$boldsymbol{1 text{kWh} = 3.6 times 10^6 text{J}}$

NEET Tip: Students should be familiar with unit conversions (Joules ↔ kWh) and power-based MCQs.

Quick Formula Box

Concept	Formula
Kinetic Energy	$boldsymbol{text{KE} = frac{1}{2}mv^2}$
Potential Energy	$boldsymbol{text{PE} = mgh}$
Work-Energy Theorem	$boldsymbol{W_{text{net}} = Delta text{KE}}$
Power	$boldsymbol{P = frac{W}{t}}$
Efficiency	$boldsymbol{frac{text{Output}}{text{Input}} times 100}$

One-Shot Mechanics Formula Sheet

Here’s a compact, NEET-ready formula sheet covering the most used formulas from Laws of Motion, Work, Energy, and Power. These are essential for concept recall and MCQ application.

Topic	Formula	NEET Tip
Newton’s 2nd Law	$boldsymbol{F = ma}$	Always start force problems with this.
Friction	$boldsymbol{f = mu N}$	Use static friction $boldsymbol{leq mu N}$ in equilibrium cases.
Inclined Plane Forces	$boldsymbol{N = mg cos theta}, boldsymbol{F = mg sin theta}$	Resolve forces into parallel & perpendicular.
Work	$boldsymbol{W = F cdot d cdot cos theta}$	$theta = 0^circ$ → max work, $theta = 90^circ$ → zero work.
KE	$boldsymbol{text{KE} = frac{1}{2}mv^2}$	Often tested in projectile/impact problems.
PE	$boldsymbol{text{PE} = mgh}$	Used with conservation of energy.
Power	$boldsymbol{P = frac{W}{t}}, boldsymbol{P = Fv}$	Instantaneous power uses velocity.

Use this table during last-minute revision and to spot formula-based MCQs.

Previous Year NEET Questions: Mechanics

Here are real NEET-style questions from 2020–2024, showing the types of MCQs you’ll face in the exam.

NEET 2024

Q1. A 5 kg block slides down a smooth incline of 30°. What is the acceleration?
A) 9.8 m/s²
B) 4.9 m/s²
C) 2.5 m/s²
D) 8.5 m/s²

Answer: B
$boldsymbol{a = g sin theta = 9.8 times sin 30^circ = 9.8 times 0.5 = 4.9 text{m/s}^2}$

NEET 2023

Q2. In the pulley system shown, the acceleration of the 2 kg block is:
(Assume ideal pulley and massless string)
[Insert simple pulley diagram with two blocks: 2 kg and 3 kg]

Answer:
Net force = $boldsymbol{(3 - 2)g = 1 times 9.8 = 9.8 text{N}}$
Total mass = $boldsymbol{5 text{kg}}$
Acceleration = $boldsymbol{frac{9.8}{5} = 1.96 text{m/s}^2}$

NEET 2022

Q3. A force does 50 J of work in moving a body by 5 m. What is the force applied?
A) 10 N
B) 5 N
C) 25 N
D) 15 N

Answer: A
Concept: $boldsymbol{W = F cdot d Rightarrow F = frac{W}{d} = frac{50}{5} = 10 text{N}}$

NEET 2021

Q4. If friction is acting opposite to the motion, the work done by friction is:
A) Positive
B) Zero
C) Negative
D) Cannot be determined

Answer: C
Concept: Friction always opposes motion → Negative work

Practice Questions: Laws of Motion & Work-Energy

Try these 5 MCQs to test your mechanics concepts.

Q1. A 10 kg block is pulled with a force of 50 N at 30° to the horizontal. Find the horizontal work done over 5 m.

A) 250 J
B) 216.5 J
C) 200 J
D) 300 J

Answer B: $boldsymbol{text{Work} = F cdot d cdot cos theta = 50 times 5 times cos 30^circ = 250 times 0.866 approx 216.5 text{J}}$

Q2. In a pulley system, two masses 4 kg and 6 kg are connected. What is the acceleration of the system?
(Take g = 9.8 m/s²)

A) 1.96 m/s²
B) 2.5 m/s²
C) 0.98 m/s²
D) 3.5 m/s²

Answer A:

Net force: $boldsymbol{(6 - 4) times 9.8 = 19.6 text{N}}$ ,

Total mass: $boldsymbol{10 text{kg}}$

Acceleration: $boldsymbol{frac{19.6}{10} = 1.96 text{m/s}^2}$

Q3. A body is moving with uniform speed in a circular path. The work done by centripetal force is:
A) Maximum
B) Zero
C) Negative
D) Positive

Answer B: Since force is perpendicular to displacement, Work = 0

Q4. A 2 kg block has an initial velocity of 4 m/s. What is its kinetic energy?
A) 4 J
B) 8 J
C) 16 J
D) 32 J

Answer C: KE = ( frac{1}{2}mv^2 = frac{1}{2} × 2 × 16 = 16 text{ J} )

Q5. What is the power if 300 J of work is done in 60 seconds?
A) 5 W
B) 10 W
C) 15 W
D) 20 W

Answer A: Power = W/t = 300 / 60 = 5 W

NEET Strategy: How to Master Mechanics

Here’s how to go from confused to confident in Mechanics:

✅ 1. Practice 200+ MCQs

Focus on Laws of Motion, Work, Energy, Power, and Pulleys. Use chapter-wise PYQ books and practice sets.

✅ 2. Prioritize Previous Year Questions

80% of NEET Mechanics questions follow repetitive formats. Solve the last 10 years’ questions twice.

✅ 3. Visualize Every Problem

Use Free Body Diagrams (FBDs) to break complex problems into simpler force components.

✅ 4. Create a Formula Flashcard

Keep a small card with all key formulas. Revise it daily. Use it just before mock tests for better recall.

✅ 5. Time Yourself

Train under exam conditions. Practice 45-minute Physics sections with topic-wise mock tests.

FAQs on Mechanics for NEET

Is Mechanics tough for NEET?

Mechanics may feel tough at first, but it becomes manageable—and even scoring—once you master core concepts like Newton’s laws, energy conservation, and friction. The key is to understand the logic behind the formulas and practice with Free Body Diagrams (FBDs) regularly. With consistent problem-solving, Mechanics becomes one of the most rewarding chapters in NEET Physics.

How many questions are asked from Mechanics?

On average, 10 to 12 questions in NEET Physics come from Mechanics-related chapters. These include:

Laws of Motion
Work, Energy & Power
Motion in a Straight Line & Plane
Gravitation
System of Particles

That’s about 40–45 marks—making Mechanics the single highest-weightage section of NEET Physics.

What is the best book for practicing Mechanics MCQs?

After building your base with NCERT and coaching notes, practice from:

DC Pandey (Arihant Series) – Topic-wise NEET MCQs with explanations
MTG NEET Previous Year Questions – Especially for understanding NEET framing
HC Verma – For conceptual clarity and problem-solving skills

Make sure to revise formulas and solve at least 200 questions per topic.

Check out our NEET Residential Coaching option for focused preparation.

Conclusion

Mechanics is the backbone of NEET Physics. It builds the foundation for many other topics like Rotational Motion, Thermodynamics, and Electrostatics. With clear understanding, formula recall, and regular MCQ practice, this section becomes not just manageable—but highly scoring.

Don’t treat Mechanics as a one-time learning chapter. Instead: