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Kinematics for JEE Main & Advanced — formulas, what is asked, and traps

JEEGenie estimates about 4% of JEE Main marks come from Kinematics. This page covers 19 formula entries, each with when to use it, what JEE asks and the traps. A common slip: Assuming motion is absolute without specifying a reference frame.

Key points to know

  • Frame of Reference & Rest/Motion. Motion is relative; an object's state is defined with respect to a chosen frame of reference. A frame is a coordinate system + a clock.
  • Distance vs Displacement. Distance is scalar (total path length), displacement is vector (shortest path from start to end). Displacement ≤ distance.
  • Speed vs Velocity. Speed is scalar (rate of distance), velocity is vector (rate of displacement). Average speed = total distance/total time; average velocity = displacement/time.
  • Instantaneous Velocity & Acceleration. Instantaneous velocity is the derivative of position; acceleration is derivative of velocity. Both are vectors.
  • Projectile Motion Basics. A projectile under gravity has constant horizontal velocity and constant vertical acceleration. Motion is 2D parabolic.
  • Uniform Circular Motion. Motion in a circle at constant speed; acceleration is centripetal (towards center) and changes direction only.
  • Relative Motion in 2D. Velocity of A relative to B: v⃗AB=v⃗A−v⃗B. Use vector subtraction.
  • Sign Convention in Kinematics. Choose a positive direction consistently. Displacement, velocity, acceleration can be positive or negative. In free fall, upward positive is common.
  • Calculus in Kinematics. For variable acceleration, use differentiation and integration: v=dxdt, a=dvdt, x=∫v dt, v=∫a dt.
  • Free Fall Under Gravity. Only force is gravity; acceleration is constant g downward. Use equations of motion with a=±g.
  • Scalars and Vectors in Kinematics. Position, displacement, velocity, acceleration are vectors. Speed, distance, time are scalars. Always treat direction.
  • Average vs Instantaneous Quantities. Average is over an interval; instantaneous is at a point. Use limits for instantaneous.

Formula sheet

NameFormulaWhen to use
Distance vs DisplacementDisplacement s⃗=r⃗f−r⃗iAlways distinguish; displacement is key for velocity, distance for speed.
Speed vs VelocityAverage speed=total distanceΔt, v⃗avg=Δs⃗ΔtUse speed for path length, velocity for position change.
Instantaneous Velocity & Accelerationv⃗=dr⃗dt, a⃗=dv⃗dt=d2r⃗dt2When motion is described by a function of time.
Equations of Motion (Constant Acceleration)v=u+at; s=ut+12at2; v2=u2+2asAny problem with uniform acceleration (e.g., free fall, motion on incline).
Graphical Analysis: v-t and x-tv=dxdt, a=dvdt, Δx=∫v dtWhen given graphs or asked to interpret motion from graphs.
Relative Motion in 1Dv⃗AB=v⃗A−v⃗BWhen two objects move along the same line (e.g., overtaking, collision).
Projectile Motion Basicsx=uxt, y=uyt−12gt2Any object launched near Earth's surface with only gravity.
Projectile: Time of Flight, Range, Max HeightT=2usin⁡θg; R=u2sin⁡2θg; H=u2sin⁡2θ2gFor level ground, no air resistance.
Projectile on Inclined PlaneFor incline angle α, launch angle θ relative to incline: ax=−gsin⁡α, ay=−gcos⁡αWhen projectile is launched up or down an incline.
Uniform Circular Motionac=v2r=ω2r, v=ωr, T=2πωAny object moving in a circular path at constant speed.
Non-Uniform Circular Motionat=dvdt, ac=v2r, anet=at2+ac2When speed is not constant (e.g., vertical loop).
Relative Motion in 2Dv⃗AB=v⃗A−v⃗BWhen two objects move in a plane (e.g., rain-man, boat-river).
River-Boat Problemsv⃗bg=v⃗bw+v⃗wg; Time to cross: t=dvbwcos⁡θ; Drift: x=(vwg−vbwsin⁡θ)tBoat crossing a river with current.
Rain-Man Problemsv⃗rm=v⃗r−v⃗mWhen a person moves in rain and needs umbrella direction.
Calculus in Kinematicsv=dxdt, a=dvdt, Δx=∫t1t2v dt, Δv=∫t1t2a dtWhen acceleration is a function of time, velocity, or position.
Motion Graphs: x-t, v-t, a-t Interconversionv=dxdt, a=dvdt, Δx=∫v dt, Δv=∫a dtWhen given one graph and asked to sketch another or find quantities.
Free Fall Under Gravityv=u±gt, s=ut±12gt2, v2=u2±2gsAny object dropped or thrown vertically near Earth.
Stopping Distance and Reaction Timestotal=v0tr+v022a (where a is deceleration)Problems involving vehicle braking or safety.
Average vs Instantaneous Quantitiesvavg=ΔxΔt, v=lim⁡Δt→0ΔxΔtWhen time interval is given vs specific time.

Open the Kinematics formula page

What JEE asks

  • Frame of Reference & Rest/Motion. JEE often asks to identify relative motion or choose the correct frame for a problem.
  • Distance vs Displacement. JEE often tests with a particle moving on a curved path; find displacement magnitude.
  • Speed vs Velocity. JEE often gives a trip with multiple segments; compute average speed and velocity separately.
  • Instantaneous Velocity & Acceleration. JEE gives x(t) and asks for v(t) or a(t) via differentiation.
  • Equations of Motion (Constant Acceleration). JEE often combines two equations to find unknowns; watch for sign conventions.
  • Graphical Analysis: v-t and x-t. JEE often gives a v-t graph and asks for displacement, acceleration, or distance traveled.
  • Relative Motion in 1D. JEE often asks time to meet or distance between moving objects using relative velocity.
  • Projectile Motion Basics. JEE often asks for time of flight, range, or maximum height.
  • Projectile: Time of Flight, Range, Max Height. JEE often asks for ratio of ranges or heights for different angles.
  • Projectile on Inclined Plane. JEE often asks for range along the incline or time of flight.
  • Uniform Circular Motion. JEE often asks for centripetal force or relation between v, ω, T.
  • Non-Uniform Circular Motion. JEE often asks for net acceleration at a point in a vertical circle.
  • Relative Motion in 2D. JEE often asks for direction to hold umbrella or boat crossing river.
  • River-Boat Problems. JEE often asks for minimum time or minimum drift conditions.
  • Rain-Man Problems. JEE often asks for angle of umbrella relative to vertical.
  • Sign Convention in Kinematics. JEE often tests sign awareness in multi-step problems.
  • Calculus in Kinematics. JEE often gives a(t) and asks for v(t) or x(t) via integration.
  • Motion Graphs: x-t, v-t, a-t Interconversion. JEE often gives a v-t graph and asks for acceleration at a point or total displacement.
  • Free Fall Under Gravity. JEE often asks for time to reach ground or height from velocity.
  • Stopping Distance and Reaction Time. JEE often asks for minimum distance to avoid collision.
  • Scalars and Vectors in Kinematics. JEE often tests vector nature in multiple-choice questions.
  • Average vs Instantaneous Quantities. JEE often asks for instantaneous velocity from position function.
  • Solving Kinematics Problems: Step-by-Step. JEE often requires combining multiple equations; systematic approach is key.

Common traps

  • Assuming motion is absolute without specifying a reference frame. Frame of Reference & Rest/Motion
  • Using distance in place of displacement in velocity calculations. Distance vs Displacement
  • Assuming average speed equals magnitude of average velocity. Speed vs Velocity
  • Forgetting that acceleration can be non-zero even when speed is constant (e.g., circular motion). Instantaneous Velocity & Acceleration
  • Using these for non-constant acceleration (requires calculus). Equations of Motion (Constant Acceleration)
  • Confusing area under v-t with distance (area gives displacement; distance is absolute area). Graphical Analysis: v-t and x-t
  • Sign errors: subtract velocities in correct order. Relative Motion in 1D
  • Assuming horizontal acceleration is non-zero. Projectile Motion Basics
  • Complementary angles (θ and 90∘−θ) give the same range since sin⁡2θ=sin⁡(180∘−2θ); maximum range is at 45∘. Projectile: Time of Flight, Range, Max Height
  • Using standard projectile formulas directly without adjusting for incline. Projectile on Inclined Plane
  • Thinking acceleration is zero because speed is constant. Uniform Circular Motion
  • Forgetting tangential component when speed changes. Non-Uniform Circular Motion
  • Adding instead of subtracting vectors. Relative Motion in 2D
  • Confusing angle of boat with direction of resultant velocity. River-Boat Problems

Topics in Kinematics

  • Motion in a Straight Line
  • Graphs of Motion
  • Relative Velocity
  • Projectile Motion
  • Motion in a Plane

Previous-year questions on Kinematics

JEEGenie has 453 previous-year questions on Kinematics. A few worked examples follow.

YearQuestions
202617
202522
202432
202338
202241
202147
202015
201954
201810
201710
20165
20154
20148
20137
20127
20116
20102
20093
20083
20074
20063
20059
200410
20038
20027
20013
20007
19996
19988
19976
19962
19955
19944
19935
19911
19901
19892
19882
19874
19864
19843
19838
19827
19812
19801

Question 1 easy

A person travelling on a straight line moves with a uniform velocity v1 for a distance x and with a uniform velocity v2 for the next 32x distance. The average velocity in this motion is 507 m/s. If v1 is 5 m/s then v2= __________ m/s.

Answer: 10

Explanation. Step 1: Total distance = x+32x=52x. Step 2: Time for first part: t1=xv1=x5. Step 3: Time for second part: t2=3x/2v2=3x2v2. Step 4: Average velocity = total distancetotal time=5x/2x/5+3x/(2v2)=52(15+32v2)=507. Step 5: Solve: 52(15+32v2)=507⇒15+32v2=720⇒32v2=320⇒v2=10. v2=10 m/s

From NTA/IIT papers: JEE Main 2025 · 2 Apr Shift 1

Question 2 hard

A block of mass 5 kg moves along the x-direction subject to the force F=(−20x+10) N, with the value of x in metre. At time t=0 s, it is at rest at position x=1 m. The position and momentum of the block at t=(π/4) s are
  1. −0.5 m, 5 kg m/s
  2. 0.5 m, 0 kg m/s
  3. 0.5 m, −5 kg m/s
  4. −1 m, 5 kg m/s

Answer: C

Explanation. The force is F=−20x+10=−20(x−12). For mass m=5 kg, a=Fm=−4(x−12). Let u=x−12. Then u¨=−4u, which is SHM with ω=2 rad/s. At t=0, x=1 so u(0)=0.5, and the block is at rest, so u˙(0)=0. Thus u(t)=0.5cos⁡(2t). At t=π4, u=0.5cos⁡(π2)=0, so x=u+0.5=0.5 m. Velocity: u˙(t)=−0.5⋅2sin⁡(2t)=−sin⁡(2t). At t=π4, u˙=−sin⁡(π2)=−1 m/s. Thus momentum p=mv=5×(−1)=−5 kg m/s. Therefore, position and momentum are 0.5 m, −5 kg m/s which is option **C**.

From NTA/IIT papers: JEE Advanced 2024

Question 3 easy

A particle starts with an initial velocity of 10.0 ms−1 along x-direction and accelerates uniformly at the rate of 2.0 ms−2. The time taken by the particle to reach the velocity of 60.0 ms−1 is __________.
  1. 30s
  2. 6s
  3. 3s
  4. 25s

Answer: D

Explanation. Using v = u + at, 60 = 10 + 2t => t = 25s

From NTA/IIT papers: JEE Main 2023 · 6 Apr Shift 2

Question 4 hard

A projectile is fired from horizontal ground with speed v and projection angle θ. When the acceleration due to gravity is g, the range of the projectile is d. If at the highest point in its trajectory, the projectile enters a different region where the effective acceleration due to gravity is g′=g0.81, then the new range is d′=nd. The value of n is ______.

Answer: 0.95

Explanation. We know the usual range is d=v2sin⁡2θg. At the highest point, the horizontal velocity is vx=vcos⁡θ, and the height is H=v2sin⁡2θ2g. In the new region, the vertical acceleration becomes g′=g0.81. From the highest point, the time to fall to the ground is found from H=12g′t′2⇒v2sin⁡2θ2g=12⋅g0.81 t′2. This simplifies to t′2=0.81 v2sin⁡2θg2⇒t′=0.9 vsin⁡θg. The time to reach the highest point in the first region was tup=vsin⁡θg. Total time of flight in the new situation: T′=tup+t′=vsin⁡θg+0.9vsin⁡θg=1.9vsin⁡θg. The horizontal range is d′=vcos⁡θ⋅T′=vcos⁡θ⋅1.9vsin⁡θg=1.9⋅v2sin⁡θcos⁡θg. Since v2sin⁡2θg=dandsin⁡2θ=2sin⁡θcos⁡θ, we have v2sin⁡θcos⁡θg=d2. Thus d′=1.9⋅d2=0.95 d. So n=0.95. 0.95

From NTA/IIT papers: JEE Advanced 2022

Frequently asked questions

How much of JEE Main comes from Kinematics?
JEEGenie estimates about 4% of JEE Main marks come from Kinematics, based on recent papers. The share varies from year to year.
Which formulas matter most in Kinematics?
The Kinematics sheet on this page has 19 formula entries, starting with Distance vs Displacement, Speed vs Velocity, Instantaneous Velocity & Acceleration, Equations of Motion (Constant Acceleration), Graphical Analysis: v-t and x-t. Each one comes with when to use it and the trap to avoid.
What topics does Kinematics cover for JEE?
Kinematics covers Motion in a Straight Line, Graphs of Motion, Relative Velocity, Projectile Motion, Motion in a Plane.
How should I revise Kinematics before the exam?
Learn each formula together with its condition of use, read the trap listed beside it, then practise questions and review every mistake. The practice link on this page opens Kinematics questions on JEEGenie.
How many previous-year questions are there on Kinematics?
JEEGenie has 453 previous-year questions on Kinematics, and this page shows a few with worked explanations.
Is practice on Kinematics free on JEEGenie?
Sign-up is free and includes a 7-day Pro trial. After the trial, free accounts keep a limited daily quota.