Gravitation ഗുരുത്വാകർഷണം
A coconut drops from a palm. The Moon goes round and round the Earth. Chandrayaan-3 landed gently on the Moon. All three happen because of one force: gravitation. Every object in the universe pulls every other object. In this chapter you will see how big that pull is, why every falling object speeds up by 9.8 m/s every second, why the Moon pulls only about one sixth as hard as the Earth, how mass differs from weight, why astronauts float, and what keeps satellites in orbit. This interactive, animated self-study guide starts with the basics from earlier classes. It then covers every idea of the chapter with Kerala examples and gives animated, exam-style solutions to every textbook question. It ends with a revision sheet and a model test with a fully solved paper.
The chapter in one picture
The red arrows are the Earth's pull, called gravity (ഭൂഗുരുത്വാകർഷണബലം). It always points towards the centre of the Earth (ഭൂകേന്ദ്രം). The coconut starts at rest, so the pull makes it fall straight down, faster and faster. The Moon is already moving sideways very fast, so the same pull keeps bending its path into a circle around the Earth. You will meet both ideas again on pages 7 and 11.
How to use this guide
🎬 Watch the animations
Apples fall, springs stretch, planets pull and satellites circle, one step at a time. Press Next ▶ or ▶▶ Auto play.
🧪 Do the virtual experiments
Move the sliders to change a mass, a distance or a height. The figure, the arrows 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 73–86), so you can match this guide with your book.
Learning path
Follow the pages in order. If you already remember force, units, powers of ten and the equations of motion well, you can skim pages 1–4. Still try their quizzes, because the chapter uses all four every day.
Quick glossary (Malayalam ↔ English)
| Textbook term | English | Meaning |
|---|---|---|
| ഗുരുത്വാകർഷണം | Gravitation | The pull that every object in the universe has on every other object |
| ഭൂഗുരുത്വാകർഷണബലം | Earth's gravitational force (gravity) | The Earth's pull on an object, always towards the centre of the Earth |
| ആകർഷണബലം · പരസ്പരാകർഷണബലം | Attractive force · mutual attractive force | A pull; two bodies pull each other with equal forces |
| സാർവിക ഗുരുത്വാകർഷണനിയമം | Universal law of gravitation | F = G m₁m₂/d²: the force varies directly as the product of the masses and inversely as the square of the distance |
| ഗുരുത്വാകർഷണസ്ഥിരാങ്കം | Gravitational constant, G | 6.67 × 10−11 N m²/kg², the same everywhere in the universe |
| ഭൂഗുരുത്വാകർഷണത്വരണം | Acceleration due to gravity, g | The acceleration the Earth's pull gives to a falling object: about 9.8 m/s² |
| ബലം · ത്വരണം | Force · acceleration | A push or pull (newton, N) · the change in velocity each second (m/s²) |
| പ്രവേഗം · ആദ്യപ്രവേഗം · അന്ത്യപ്രവേഗം | Velocity · initial velocity (u) · final velocity (v) | Speed in a stated direction (m/s); its value at the start and at the end |
| സമവേഗം · സമപ്രവേഗം | Uniform speed · uniform velocity | Equal distances in equal times · the same speed and the same direction |
| മാസ് | Mass | The quantity of matter in an object (kg); the same everywhere |
| ഭാരം | Weight | The force with which the Earth (or the Moon, a planet…) pulls an object: W = mg, in newtons |
| കിലോഗ്രാം ഭാരം (kgwt) | Kilogram weight | The Earth's pull on a 1 kg mass: 1 kgwt = 9.8 N |
| കോമൺ ബാലൻസ് · സ്പ്രിങ് ബാലൻസ് · പ്ലാറ്റ്ഫോം ബാലൻസ് | Common (beam) balance · spring balance · platform balance | The first compares masses; the other two measure the pull (weight) |
| ചലനനിയമം · രണ്ടാം ചലനനിയമം | Law of motion · second law of motion | Newton's laws; the second is F = ma |
| നേർ അനുപാതം · വിപരീത അനുപാതം | Direct proportion · inverse proportion | One doubles when the other doubles · one halves when the other doubles |
| വർഗം · ഗുണനഫലം | Square · product | d² = d × d · the result of multiplying (m₁ × m₂) |
| അകലം · ആരം | Distance (separation) · radius | d between the centres of two bodies · R of the Earth, 6.4 × 10⁶ m |
| ഭൂകേന്ദ്രം · ഭൗമോപരിതലം | Centre of the Earth · Earth's surface | Gravity points to the centre; g ≈ 9.8 m/s² at the surface |
| ധ്രുവപ്രദേശം · ഭൂമധ്യരേഖാപ്രദേശം | Polar region · equatorial region | g is largest at the poles (≈ 9.83 m/s²), smallest at the equator (≈ 9.78 m/s²) |
| ഖഗോളങ്ങൾ | Celestial bodies | The Sun, the Moon, planets, stars |
| വേലിയേറ്റം · വേലിയിറക്കം | High tide · low tide | The rise and fall of the sea, caused by the pull of the Moon and the Sun |
| നിർബാധ പതനം | Free fall | Falling under gravity alone |
| ഭാരമില്ലായ്മ | Weightlessness | Feeling no weight because you and your support fall together |
| വർത്തുളചലനം · സമവർത്തുളചലനം | Circular motion · uniform circular motion | Moving along a circle · covering equal distances along it in equal times |
| തൊടുവര | Tangent | The straight line that just touches a circle; a released stone flies off along it |
| അഭികേന്ദ്രത്വരണം · അഭികേന്ദ്രബലം | Centripetal acceleration · centripetal force | The acceleration and the force towards the centre that keep a body on a circle |
| ഉപഗ്രഹം · കൃത്രിമ ഉപഗ്രഹം | Satellite · artificial satellite | A body that goes round a planet (the Moon; Chandrayaan, communication satellites) |
| തമോഗർത്തം | Black hole | A body whose gravity is so strong that not even light can escape |
| സോഫ്റ്റ് ലാൻഡിങ് | Soft landing | Slowing a lander down gently so that it touches the Moon without crashing |
| തൂവലും നാണയവും പരീക്ഷണം | Feather and coin experiment | Without air, a feather and a coin fall together |
| 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 12–13) |
🌐 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 from PhET, NASA, ISRO and YouTube. Those links need internet and open in a new tab. All of them are collected in the resources hub on page 14.
- ▶️ KITE VICTERS ശാസ്ത്ര വിചാരം - ഗ്രാവിറ്റി | Gravity by Vaisakhan Thampi Epi - 19 YouTube – itsvicters (KITE VICTERS) · 27:02
Kerala's official educational channel: physicist Vaisakhan Thampi talks about gravity in Malayalam (general science talk, not a textbook class). - ▶️ Class 9 Physics | Gravitation / ഗുരുത്വാകർഷണം | Full Chapter | Exam Winner YouTube – Exam Winner Class 9 · 13:03
Quick Malayalam run-through of the new SCERT Class 9 Gravitation chapter (private tuition channel). - ▶️ Class 9 Physics | GRAVITATION | ഗുരുത്വാകർഷണം | 15 മിനിറ്റിൽ പഠിക്കാം! 🔥 YouTube – PW Keralam Class 9 · 15:03
15-minute Malayalam summary of the chapter (private tuition channel). - 📄 What Is Gravity? (NASA Space Place) NASA
A short, friendly NASA page explaining what gravity is and why everything pulls on everything else.
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.