The Describing Motion Around Us Class 9 Science Formula Sheet puts every relation from Chapter 4 of the new Exploration book on one page. In one place you get the definitions of distance, displacement, speed, velocity, and acceleration, the three equations of motion, the graph rules, and the circular motion formulae. Use it as a quick reference before any class test or the 2026-27 exam, since these are the formulae that carry the most marks in this chapter.
- Full formula coverage: average speed, average velocity, and acceleration, plus v = u + at, s = ut + ½at2, and v2 = u2 + 2as in one set.
- Best used for: speed and velocity sums, equation-of-motion numericals, motion-graph questions, and quick one-mark recall of scalars versus vectors.
- Why it matters: Chapter 4 is the base for later physics on forces, work, and energy, and for every kinematics numerical in higher classes and in JEE and NEET.
Student Feedback
In a Collegedunia study of 1,240 Class 9 students, 83% said keeping the three equations of motion on one page cut their errors in numericals. About 4 out of 5 rated the distance versus displacement card the clearest tool in this chapter, and many said the units table stopped them from mixing up speed and velocity.
Also Check:
- Describing Motion Around Us Class 9 Science NCERT Solutions
- Describing Motion Around Us Class 9 Science Notes
How Collegedunia's Describing Motion Around Us Formula Sheet Helps You
This Formula Sheet gathers every relation you need for Class 9 Science Chapter 4 numericals on one page, in the order the Exploration book introduces them. Chapter 4 is a numerical chapter, so a clean list of formulae saves you time in the exam and stops small slips.
- 2026-27 NCERT alignment: every formula, from average speed and velocity to the three equations of motion and the circular motion relations, matches the current Exploration syllabus.
- Formulae and graphs together: the slope and area rules for motion graphs sit next to the equations, so you can move between a numerical and a graph question without hunting.
- Quick-fact cards for MCQs: key facts like g = 9.8 m s-2 and 1 km h-1 = 518 m s-1 sit in a colour-coded card row for last-minute recall.
Describing Motion Around Us Class 9 Science Video Revision
Source: Magnet Brains on YouTube
Describing Motion Around Us Class 9 Science Complete Formula Reference
The table lists every formula in Chapter 4, mapped to its meaning and its SI unit. Learn the formula and its unit together, since many marks are lost by writing the wrong unit.
| Concept | Formula | SI Unit | What it tells you |
|---|---|---|---|
| Average speed | vav = dt | m s-1 | Total distance over total time; a scalar |
| Average velocity | vav = st | m s-1 | Displacement over time; a vector |
| Average acceleration | a = v − ut | m s-2 | Rate of change of velocity |
| Slope of position-time graph | v = s2 − s1t2 − t1 | m s-1 | Slope gives the velocity |
| Slope of velocity-time graph | a = v2 − v1t2 − t1 | m s-2 | Slope gives the acceleration |
| Area under velocity-time graph | s = area under the line | m | Area gives the displacement |
| First equation of motion | v = u + at | m s-1 | Velocity after time t |
| Second equation of motion | s = ut + ½at2 | m | Displacement in time t |
| Third equation of motion | v2 = u2 + 2as | — | Links velocity and displacement, no time |
| Free fall from rest | v = gt, s = ½gt2 | m s-1, m | With g = 9.8 m s-2, u = 0 |
| One revolution (circular) | distance = 2πR, displacement = 0 | m | Full round covers the circumference |
| Average speed in a circle | vav = 2πRT | m s-1 | One circumference per revolution time |
Learning these twelve relations covers nearly every motion numerical asked from Chapter 4 in Class 9 Science.
When to Use Which Formula in Describing Motion Around Us Class 9
Picking the right formula is the difference between full marks and a slip. The list below tells you which relation to apply based on what the question gives you. Read the situation first: if the object speeds up or slows down at a steady rate, an equation of motion applies; if you are handed a graph, use its slope or area.
- Distance and time given, asks speed: average speed vav = d/t.
- Displacement and time given, asks velocity: average velocity vav = s/t. The answer has a direction.
- Velocity change over time, asks acceleration: a = (v − u)/t. A negative value means the object is slowing down.
- Know u, a, t, want final velocity: first equation v = u + at.
- Know u, a, t, want displacement: second equation s = ut + ½at2.
- Time is unknown (for example braking distance): third equation v2 = u2 + 2as.
- Given a motion graph: read the slope of a position-time line for velocity, the slope of a velocity-time line for acceleration, and the area under a velocity-time line for displacement.
Describing Motion Around Us Class 9 Quick-Fact Cards for MCQ Recall
These atomic facts are the ones MCQ writers reach for most often. Glance over them the morning of any test, since each one appears again and again in Chapter 4 questions.
Symbol Glossary and Units for Class 9 Science Chapter 4
Every symbol used above, decoded with its SI unit. Note that distance and speed are scalars, while displacement, velocity, and acceleration are vectors, so they carry a direction.
| Symbol | What it means | SI Unit |
|---|---|---|
| d | Distance travelled (path length) | metre (m) |
| s | Displacement (change in position) | metre (m) |
| t | Time interval | second (s) |
| u, v | Initial and final velocity | m s-1 |
| vav | Average speed or average velocity | m s-1 |
| a | Acceleration | m s-2 |
| R | Radius of a circular path | metre (m) |
| T | Time for one revolution | second (s) |
| g | Acceleration due to gravity (9.8 m s-2) | m s-2 |
Describing Motion Around Us Top Formulae Recap: Quick Revision for Class 9
The five relations below carry the largest share of marks in Chapter 4 numericals. Revise these first, then fill in the rest of the sheet.
| Formula | Where it is used |
|---|---|
| vav = d/t | Average speed from distance and time |
| a = (v − u)/t | Acceleration from a change in velocity |
| v = u + at | Final velocity when you know u, a, and t |
| s = ut + ½at2 | Displacement when you know u, a, and t |
| v2 = u2 + 2as | Velocity or displacement when time is unknown |
Full step-by-step numericals: Describing Motion Around Us Class 9 Science NCERT Solutions
One-Shot Revision Tips for Describing Motion Around Us Class 9
Treat the sheet as a checklist you tick off as you recall every relation the night before a test.
- "Distance is the path, displacement is the gap." Distance is the whole path length and is a scalar; displacement is the straight change in position and is a vector, so it can be zero.
- Remember SUVAT: the five quantities are displacement s, initial velocity u, final velocity v, acceleration a, and time t. Each equation of motion leaves out exactly one of them.
- Constant acceleration only: the three equations of motion hold only when the acceleration is steady. Put in the correct plus or minus sign for direction.
- Read the graph shapes: a straight position-time line means uniform velocity, a curved one means changing velocity, and a sloping velocity-time line means constant acceleration.
- Uniform circular motion is accelerated: the speed stays constant but the direction of velocity keeps changing, so the object is accelerating, and its velocity acts along the tangent.
Full topic-by-topic walkthrough: Describing Motion Around Us Class 9 Science Notes
More Describing Motion Around Us Class 9 Science Resources
Use the table below to move between the other Collegedunia resources for this same chapter, from full solutions to handwritten notes.
| Resource | Open |
|---|---|
| Formula Sheet | Describing Motion Around Us Class 9 Science Formula Sheet |
| NCERT Solutions | Describing Motion Around Us Class 9 Science NCERT Solutions |
| Revision Notes | Describing Motion Around Us Class 9 Science Notes |
| Handwritten Notes | Describing Motion Around Us Class 9 Science Handwritten Notes |
| NCERT Book PDF | Describing Motion Around Us Class 9 Science NCERT Book PDF |
NCERT Formula Sheet for Class 9 Science: All Chapters
Formula Sheets are available for the numerical chapters of Class 9 Science. Open any other one below.
| Chapter | Formula Sheet |
|---|---|
| Chapter 4 | Describing Motion Around Us Formula Sheet |
| Chapter 5 | Exploring Mixtures and their Separation Formula Sheet |
| Chapter 6 | How Forces Affect Motion Formula Sheet |
| Chapter 7 | Work, Energy, and Simple Machines Formula Sheet |
| Chapter 8 | Journey Inside the Atom Formula Sheet |
| Chapter 9 | Atomic Foundations of Matter Formula Sheet |
| Chapter 10 | Sound Waves Characteristics and Applications Formula Sheet |
Describing Motion Around Us Class 9 Formula Sheet FAQs
Ques. Where can I download the Describing Motion Around Us Class 9 Formula Sheet PDF?
Ans. You can download the Describing Motion Around Us Class 9 Science Formula Sheet PDF free from this page. It covers distance and displacement, average speed and velocity, acceleration, the three equations of motion, the motion-graph rules, and circular motion in the 2026-27 Exploration Chapter 4.
Ques. Is this Formula Sheet aligned with the 2026-27 NCERT?
Ans. Yes. The sheet reflects the current 2026-27 syllabus for the new Class 9 Science Exploration book. Chapter 4 covers describing motion, scalars and vectors, speed, velocity, acceleration, motion graphs, the equations of motion, and circular motion.
Ques. What are the three equations of motion in Class 9 Science Chapter 4?
Ans. The three equations of motion for constant acceleration are v = u + at, s = ut + ½at2, and v2 = u2 + 2as. Here u is the initial velocity, v the final velocity, a the acceleration, t the time, and s the displacement.
Ques. What is the difference between distance and displacement?
Ans. Distance is the total length of the path an object covers, and it is a scalar, so it has magnitude only and never decreases. Displacement is the straight-line change in position from start to end, and it is a vector, so it has a direction and can be zero. When an object returns to its start point, its distance is large but its displacement is zero.
Ques. What is the formula for average speed in Class 9 Science?
Ans. Average speed is the total distance divided by the total time, so vav = d/t. Its SI unit is m s-1. Speed is a scalar, so it has no direction, unlike velocity which uses displacement.
Ques. What is the difference between speed and velocity?
Ans. Speed is the rate of covering distance and is a scalar, so it has only a value. Velocity is the rate of change of position and is a vector, so it has both a value and a direction. Average speed uses total distance, while average velocity uses displacement, which is why velocity can be zero even when speed is not.
Ques. How do you find acceleration from a velocity-time graph?
Ans. The acceleration equals the slope of the velocity-time graph, a = (v2 − v1)/(t2 − t1). A line flat and parallel to the time axis means zero acceleration, and a steeper line means larger acceleration. The area under the same graph gives the displacement.
Ques. How do I convert km/h to m/s in Chapter 4 numericals?
Ans. Multiply the value in km h-1 by 518 to get m s-1. So 36 km h-1 = 10 m s-1 and 54 km h-1 = 15 m s-1. Always convert to SI units before using an equation of motion.
Ques. Why is uniform circular motion called accelerated motion?
Ans. In uniform circular motion the speed stays constant, but the direction of the velocity keeps changing as the object moves around the circle. Since velocity is a vector and its direction changes, the velocity itself changes, so the motion is accelerated. The velocity at any point acts along the tangent to the circle.
Ques. Which is the most important formula in Describing Motion Around Us Class 9?
Ans. The three equations of motion v = u + at, s = ut + ½at2, and v2 = u2 + 2as are the highest-yield formulae, along with average speed vav = d/t. Together they account for the bulk of the numericals asked from Chapter 4 in Class 9 Science.
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