Gravitation is the force of attraction between any two objects in the universe due to their masses. It’s a universal force that acts on all objects.
The force of attraction between two masses is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
Where:
The acceleration experienced by an object due to Earth’s gravitational pull.
Where:
Value on Earth: 9.8 m/s²
🌍 Your phone on the table is attracted by Earth — that’s gravity. Even your fries have weight.
📱 When you drop your phone, it falls at 9.8 m/s² — that’s g pulling it down.
2021 Shift MCQ: Unit of G?
Answer: Nm²/kg²
2022 Shift 1: Value of g on Earth’s surface?
Answer: 9.8 m/s²
Gravitational acceleration decreases with altitude.
Where h is the height above Earth’s surface.
Energy due to the position of an object in a gravitational field.
Negative because the force is attractive.
The minimum speed needed to escape Earth’s gravitational pull.
For Earth: vₑ ≈ 11.2 km/s
✈️ Less gravity at airplane altitude than on the ground.
🛌 Earth’s gravity always pulls you back when you try to jump out of bed early morning.
🚀 You need to hit 11.2 km/s to escape Earth’s gravity — like a rocket launch.
| Formula | Meaning |
|---|---|
| \( F = G \frac{m_1 m_2}{r^2} \) | Universal Gravitational Force |
| \( g = \frac{G M}{R^2} \) | Acceleration due to gravity |
| \( g_h = g \left(1 - \frac{2h}{R}\right) \) | g at height |
| \( U = -\frac{G m_1 m_2}{r} \) | Gravitational potential energy |
| \( v_e = \sqrt{\frac{2 G M}{R}} \) | Escape velocity |
2021 Shift 2: Unit of gravitational constant G (theory MCQ)
2022 Shift 1: Value of g at Earth’s surface
2023 Dec: No direct Q — but fair game for theory filler MCQs
| Concept | Gen Z Example |
|---|---|
| Gravity attracts all masses | Earth pulling your sneakers |
| g value decreases with altitude | You weigh a fraction less on an airplane |
| Escape velocity | How fast a rocket must go to ditch gravity |
| Negative Potential Energy | You always get pulled back by gravity |
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