JEE Main Physics · Laws of Motion PYQ
JEE Main Laws of Motion PYQ (2002–2026)
Laws of Motion is a P2 Mechanics foundation chapter — ~4% JEE Main weightage with 1 question per session. Prerequisite for Rotational Motion, Work-Energy-Power and most Oscillations problems. Free-body diagrams and constraint relations are the recurring skills.
Laws of Motion PYQs from 2002 to 2026, covering Newton's three laws, friction, pseudo forces in non-inertial frames, pulley systems and constraint relations. Every solution includes the free-body diagram.
Laws of Motion at a Glance
Try 5 Real Laws of Motion PYQs
5 real JEE Main questions on Laws of Motion, straight from past papers. Try them, then check the answer.
- Q1JEE Main 2026 (Online) 28th January Morning Shift
A particle of mass $m$ falls from rest through a resistive medium having resistive force, $F$${}=-k v$, where $v$ is the velocity of the particle and $k$ is a constant. Which of the following graphs represents velocity $(v)$ versus time $(t)$ ?
- Q2JEE Main 2025 (Online) 28th January Evening Shift
A balloon and its content having mass M is moving up with an acceleration ‘a’. The mass that must be released from the content so that the balloon starts moving up with an acceleration ‘3a’ will be
(Take ‘g’ as acceleration due to gravity)
$ \frac{3Ma}{2a + g} $
$ \frac{2Ma}{3a + g} $
$ \frac{3Ma}{2a - g} $
$ \frac{2Ma}{3a - g} $
- Q3JEE Main 2024 (Online) 1st February Evening ShiftA cricket player catches a ball of mass 120 g moving with $25 \mathrm{~m} / \mathrm{s}$ speed. If the catching process is completed in 0.1 s then the magnitude of force exerted by the ball on the hand of player will be (in SI unit) :
- 30
- 24
- 12
- 25
- Q4JEE Main 2023 (Online) 29th January Evening Shift
The time taken by an object to slide down 45$^\circ$ rough inclined plane is n times as it takes to slide down a perfectly smooth 45$^\circ$ incline plane. The coefficient of kinetic friction between the object and the incline plane is :
- $1 - {1 \over {{n^2}}}$
- $1 + {1 \over {{n^2}}}$
- $\sqrt {1 - {1 \over {{n^2}}}} $
- $\sqrt {{1 \over {1 - {n^2}}}} $
- Q5JEE Main 2022 (Online) 26th July Morning Shift
Three masses $M$${}=100 \mathrm{~kg}, \mathrm{~m}_{1}$${}=10 \mathrm{~kg}$ and $\mathrm{m}_{2}$${}=20 \mathrm{~kg}$ are arranged in a system as shown in figure. All the surfaces are frictionless and strings are inextensible and weightless. The pulleys are also weightless and frictionless. A force F is applied on the system so that the mass $\mathrm{m}_{2}$ moves upward with an acceleration of $2 \mathrm{~ms}^{-2}$. The value of F is :
( Take $\mathrm{g}$${}=10 \mathrm{~ms}^{-2}$ )
- 3360 N
- 3380 N
- 3120 N
- 3240 N
Practise the full Laws of Motion set
Every past-paper question of this chapter, with solutions, timing and your accuracy tracked.
Key Sub-Topics & What's Tested
Newton's Laws of Motion
First law (inertia), second law (F = ma), third law (action-reaction). Inertial vs non-inertial frames.
Free-Body Diagrams (FBD)
Identifying all forces on a body, resolving along chosen axes, applying ΣF = ma in each direction.
Friction
Static friction (μ_s N ≥ f_s), kinetic friction (f_k = μ_k N), direction of friction (opposes relative motion tendency or relative motion).
Inclined Planes
Block on incline (with/without friction), forces resolved along and perpendicular to incline, limiting angle of friction.
Pulleys & Constraint Relations
Single & multiple pulleys, constraint: length of string constant → accelerations related, modified Atwood machine problems.
Pseudo Forces in Non-Inertial Frames
Applying F = ma in accelerating frame requires adding -ma_frame as pseudo force. Common in car/train accelerating systems.
Circular Motion Foundation
Uniform circular motion, centripetal force (mv²/r or mω²r), conical pendulum, banking of roads.
Momentum & Impulse
Linear momentum p = mv, impulse J = F·dt = Δp, conservation in collisions and explosions.
Question Type Distribution
| Question Type | Share (approx) | Example Pattern |
|---|---|---|
| FBD + Newton's Second Law | 30% | Block of mass 5kg on horizontal surface with friction μ=0.3, pushed by 30N horizontal force — find acceleration. |
| Pulley Problems | 20% | Atwood machine with masses 5kg and 3kg — find acceleration and tension in string. |
| Inclined Plane Problems | 15% | Block on 30° incline with coefficient of friction 0.2 — find acceleration if pushed up or let slide down. |
| Friction Problems | 15% | Minimum force to prevent block from sliding on vertical wall pressed by horizontal force. |
| Constraint Relations | 10% | Two blocks connected by string over pulley, string inextensible — relate their accelerations. |
| Impulse & Momentum | 10% | Ball of mass 100g hits wall at 10 m/s and rebounds at 8 m/s in 0.01s — find average force on wall. |
How to Solve Laws of Motion PYQs
- 1Always draw FBD first. Label every force on the body: weight (mg), normal reaction (N), applied force, friction (direction based on tendency), tension. No FBD = no problem.
- 2Pick axes carefully. For inclined plane, choose axes along and perpendicular to incline, not horizontal/vertical. For pulley, axis along string direction.
- 3Friction direction: opposes motion or tendency. Static friction opposes tendency of motion. Kinetic friction opposes actual motion direction.
- 4Constraint relations from string inextensibility. If two blocks connected by string, their velocities along string direction are equal (magnitude). Same for accelerations.
- 5Pseudo force in accelerating frames. In a frame accelerating with a_frame, add pseudo force -m·a_frame on each body. Then apply Newton's laws as usual.
Common Mistakes That Cost Marks
- Forgetting weight in FBD. Every body has mg acting downward. Missing it gives half-answers.
- Wrong friction direction. Friction opposes motion or tendency of motion, not the applied force. If applied force is just shy of overcoming friction, friction still acts opposite to potential motion direction.
- Using μ_s for kinetic friction problems. Static μ_s applies when body is at rest (or about to move). Kinetic μ_k applies when actually sliding. μ_k < μ_s usually.
- Ignoring normal reaction changes on incline. Normal reaction on incline = mg·cos(θ), not mg. Affects friction calculation (f = μ·mg·cos(θ)).
- Applying Newton's laws in non-inertial frames without pseudo force. Car accelerating → frame inside car is non-inertial → add pseudo force to use F = ma.
Related JEE Main Practice
Frequently asked questions
How many Laws of Motion PYQs should I solve?
Target 50–70 PYQs across 2010–2026. Foundation chapter for all Mechanics — strong practice here accelerates Rotational Motion, WPE and Oscillations.
Is Laws of Motion harder than Rotational Motion?
Conceptually simpler. Laws of Motion deals with linear motion of point particles. Rotational Motion adds moments of inertia and angular quantities. Master Laws of Motion first.
Do I need to draw FBD for simple problems?
Yes always — even for 'obvious' problems. FBD prevents sign errors and force-mixing. Classic mistake: missing tension in pulley systems or friction on inclines.
What's the most-tested Laws of Motion pattern?
Pulley systems with two or more blocks, friction-incline combinations. Appears in 3-4 PYQs per 10-year window. Master the constraint relation technique.
When are pseudo forces applied?
Only in non-inertial (accelerating) reference frames. In inertial frames (ground frame), no pseudo force. If problem says 'inside accelerating car', pseudo force is needed.
Does this chapter connect with Rotational Motion?
Yes — Rotational Motion is analogous to Laws of Motion (torque ↔ force, moment of inertia ↔ mass, angular acceleration ↔ linear acceleration). Strong Laws foundation → easier Rotational.
Start Laws of Motion PYQs free
Mechanics foundation. PYQs on Newton's laws, friction, pulleys, constraint relations. Sign in in 30 seconds.
Start Free Practice