Equations of Motion ചലനസമവാക്യങ്ങൾ
A train is about to cross the bridge over the Bharathapuzha. Can you work out exactly how long it will take to cross the bridge completely? The textbook opens with this question, and by the end of the chapter you will answer it and much more. You will learn how far something has really moved (displacement), how fast and in which direction (velocity), how quickly the velocity changes (acceleration), how to draw and read motion graphs, and the three equations of motion. You will also learn the road signs and road rules that keep you safe. This interactive, animated self-study guide starts from the basics: directions, units, graphs and formulas. It explains every idea with Kerala examples, solves every textbook question in exam layout, and ends with a revision sheet and a model test.
The chapter in one picture
The train is 200 m long and the bridge is 800 m long. The train starts from rest at the station and speeds up steadily: its velocity (പ്രവേഗം) grows by 1 m/s every second. That is an acceleration (ത്വരണം) of 1 m/s². After 20 s it is moving at 20 m/s, just as the engine reaches the bridge. From then on it keeps a uniform velocity (സമപ്രവേഗം) of 20 m/s. To cross completely, the engine must travel the whole bridge plus the train's own length: 800 m + 200 m = 1000 m, and 1000 m ÷ 20 m/s = 50 s. The graph below the picture is a velocity–time graph (പ്രവേഗ-സമയ ഗ്രാഫ്). The sloping part shows the speeding up and the flat part shows the steady velocity. The shaded area under the flat part is 20 × 50 = 1000 m, the distance the train covers while it crosses. You will learn all of this on pages 5–11.
How to use this guide
🎬 Watch the animations
Trains cross bridges, buses speed up, motorbikes brake and graphs draw themselves, one step at a time. Press Next ▶ or ▶▶ Auto play.
🧪 Do the virtual experiments
Move the sliders to change a speed, a time or an acceleration. The picture, the graph and the numbers all update together, exactly as the physics says.
✍️ Try before you see
Every numerical is laid out the exam way: Given → Formula → Substitution → Answer with unit. Use 💡 Show a hint first and work in your notebook. Then open ✅ Show final answer.
📖 Textbook words
Purple മലയാളം words are the exact terms used in your textbook (pages 27–52), so you can match this guide with your book.
Learning path
Follow the pages in order. If you are already confident with directions and signs, units and km/h, graphs, and rearranging formulas, you can skim pages 1–4. Still try their quizzes, because the chapter uses these skills on every page.
Quick glossary (Malayalam ↔ English)
| Textbook term | English | Meaning |
|---|---|---|
| ചലനസമവാക്യങ്ങൾ | Equations of motion | The chapter title; the three equations v = u + at, s = ut + ½at², v² = u² + 2as |
| ചലനം | Motion | A change of position with time |
| ദൂരം · സഞ്ചരിച്ച ദൂരം | Distance · distance travelled | The total length of the path actually travelled; it only has a size |
| സ്ഥാനാന്തരം | Displacement | The straight-line distance from the start to the end, with its direction; symbol s, unit m |
| ആദ്യസ്ഥാനം / അന്ത്യസ്ഥാനം | Initial / final position | Where the motion starts / where it ends |
| സഞ്ചാരപാത | Path | The route actually followed (straight or curved) |
| സദിശ അളവുകൾ · അദിശ അളവുകൾ | Vector quantities · scalar quantities | Have size and direction (displacement, velocity, acceleration) · have only size (distance, speed, time) |
| പോസിറ്റീവ് / നെഗറ്റീവ് | Positive / negative | The + and − signs that show the two directions along a line (east +, west −) |
| കിഴക്ക് / പടിഞ്ഞാറ് / വടക്ക് / തെക്ക് | East / west / north / south | The four main directions |
| വേഗം | Speed | Distance travelled per second; unit m/s |
| പ്രവേഗം | Velocity | Displacement per second, v = s/t; unit m/s, with a direction |
| സമപ്രവേഗം / അസമപ്രവേഗം | Uniform / non-uniform velocity | Equal displacements in equal times in one direction / the speed or the direction changes |
| വർത്തുളപാത | Circular path | A path along a circle; the direction keeps changing |
| ചലനദിശ | Direction of motion | The way the object is moving at that instant |
| ത്വരണം | Acceleration | Change in velocity per second, a = (v − u)/t; unit m/s² |
| ആദ്യപ്രവേഗം / അന്ത്യപ്രവേഗം | Initial / final velocity | u (at the start of the time interval) / v (at its end) |
| പ്രവേഗമാറ്റം · പ്രവേഗമാറ്റത്തിന്റെ നിരക്ക് | Change in velocity · rate of change of velocity | v − u · (v − u) ÷ t, which is the acceleration |
| മന്ദീകരണം · നെഗറ്റീവ് ത്വരണം | Retardation · negative acceleration | The rate at which velocity decreases (slowing down); a = −2 m/s² means a retardation of 2 m/s² |
| സമത്വരണം / അസമത്വരണം | Uniform / non-uniform acceleration | Equal change of velocity in equal times / unequal changes |
| ആക്സിലറേറ്റർ | Accelerator | The part of a vehicle used to increase its velocity |
| റോഡ് സൈനുകൾ | Road signs | Boards that give rules, warnings and information to road users |
| മാൻഡേറ്ററി സൈനുകൾ · കോഷനറി സൈനുകൾ · ഇൻഫോമേറ്ററി സൈനുകൾ | Mandatory · cautionary · informatory signs | Red circle: must obey · red triangle: warning · blue rectangle: information |
| റോഡ് മാർക്കിംഗ് · സീബ്രാ ക്രോസിങ് | Road marking · zebra crossing | Lines painted on the road · the striped place where pedestrians cross |
| ഗ്രാഫ് | Graph | A picture that shows how one quantity changes with another |
| X അക്ഷം / Y അക്ഷം · മൂലബിന്ദു | X-axis / Y-axis · origin | The horizontal / vertical number lines of a graph · the point O where they meet |
| തോത് | Scale | How much one centimetre on the graph stands for, e.g. 1 cm = 2 s |
| സ്ഥാന-സമയ ഗ്രാഫ് | Position–time graph | Position on the Y-axis against time on the X-axis; its slope is the velocity |
| പ്രവേഗ-സമയ ഗ്രാഫ് | Velocity–time graph | Velocity against time; its slope is the acceleration and the area under it is the displacement |
| പരപ്പളവ് | Area | The space enclosed by a shape; under a v–t graph it gives the displacement |
| നേർരേഖ · ചരിവുള്ള നേർരേഖ · വക്രരേഖ | Straight line · sloping straight line · curve | The shapes a graph line can have |
| ഭൗതിക അളവ് | Physical quantity | Something that can be measured and has a unit (length, time, velocity…) |
| പ്രവർത്തനം · സയൻസ് ഡയറി | Activity · science diary | Things to do, and the notebook where you write what you found |
| വിലയിരുത്താം · തുടർപ്രവർത്തനങ്ങൾ | Let us assess · extended activities | The end-of-chapter questions and projects (solved on pages 13–14) |
🌐 Explore online (optional)
Everything in this guide works offline: each page is a single file with no internet needed. Some pages also have blue “🌐 Explore online” boxes. They link to free simulations and videos, including Malayalam explainers. Those links need internet and open in a new tab. All of them are collected in the resources hub on page 15.
- ▶️ KITE VICTERS STD 09 Physics Class 14 (First Bell-ഫസ്റ്റ് ബെല്‍) KITE VICTERS (official, itsvicters) - First Bell · 22:42
Malayalam class (2020–21 First Bell, may follow the older syllabus; topic judged from the preview): deriving s = ut + 1/2 at^2 from the velocity-time graph. - ▶️ KITE VICTERS STD 09 Physics Class 15 (First Bell-ഫസ്റ്റ് ബെല്‍) KITE VICTERS (official, itsvicters) - First Bell · 28:34
Malayalam class (2020–21 First Bell, may follow the older syllabus; topic judged from the preview): drawing a velocity-time graph and finding displacement as the area under it. - ▶️ KITE VICTERS STD 09 Physics Class 16 (First Bell-ഫസ്റ്റ് ബെല്‍) KITE VICTERS (official, itsvicters) - First Bell · 20:46
Malayalam class (2020–21 First Bell, may follow the older syllabus; topic judged from the preview): numericals on equations of motion, including km/h to m/s conversion. - ▶️ KITE VICTERS STD 09 Physics Class 17 (First Bell-ഫസ്റ്റ് ബെല്‍) KITE VICTERS (official, itsvicters) - First Bell · 25:57
Malayalam class continuing motion problems - slowing down from 200 m/s to 100 m/s (retardation). - ▶️ Class 9 Physics | Chapter : Equations of Motion / ചലന സമവാക്യങ്ങൾ | Xylem Class 9 Xylem Class 9 (private tuition channel) · 12:48
A 13-minute Malayalam summary of the chapter ചലന സമവാക്യങ്ങൾ. - 📄 Measuring distance using the SR04 ultrasound echo module - ExpEYES ExpEYES (IUAC / official project site)
The textbook's ExpEYES activity: the SR04 sends sound pulses and times the echo to measure distance. - 📄 ExpEYES ExpEYES (IUAC / official project site)
Home of ExpEYES, the low-cost lab kit used in Kerala schools through KITE. - ▶️ ExpEYES Graphical User Interface ExpEYES (official YouTube channel) · 16:58
Tour of the ExpEYES software you use to record and plot experiment data. - 📄 Physics Tutorial - 1D Kinematics The Physics Classroom
One place covering the whole chapter: words of motion, graphs, free fall and the equations.
Made for self-learning. Works offline – every page is a single file. Study material prepared by Claude for Madhu's family study folder, October 2026.