Gravitation
Main Concepts
Gravitation- Gravitation is the universal force of attraction that acts
between all objects which have mass. It pulls objects toward each other,
which makes them come closer. This force keeps planets orbiting the
Sun and causes objects to fall toward Earth. If gravitation pull didn’t
existed the planets had gone out of solar system and everything would
be flying on earth.
Universal Law- Every object attracts and pull each other towards them
due to the gravitation pull that exists on every object (F = G m1m2/d²).
Gravity on Earth- The amount of gravitational pull on earth is 9.8 m/s²
which pulls everything towards centre.
10 Key Facts
G = Universal gravitational constant (6.67 × 10^-11)
Mass = Amount of matter (constant everywhere)
Weight = mg (force due to gravity)
Free fall = All objects same acceleration (9.8 m/s²)
Moon gravity = 1/6th Earth (jump higher)
Buoyancy = Upward force by liquid/gas
Thrust = Force perpendicular to surface
Pressure = Force/Area
Density = Mass/Volume
Relative density = Density of substance/Density of water
6 Exam MCQs
1. F = G ? (a) m1m2/d² ✓ (b) md
2. Earth gravity: (a) 9.8 m/s² ✓ (b) 1.6 m/s²
3. Weight depends on: (a) mass only (b) gravity ✓
4. Moon weight: (a) same (b) 1/6th ✓
5. Buoyant force = ? (a) weight liquid displaced ✓
6. 1 atm = (a) 10^5 Pa ✓ (b) 10^3 Pa
Quick Revision
Trick: Mass(everywhere same) Weight(changes with g)
Main Concepts
Gravitation- Gravitation is the universal force of attraction that acts
between all objects which have mass. It pulls objects toward each other,
which makes them come closer. This force keeps planets orbiting the
Sun and causes objects to fall toward Earth. If gravitation pull didn’t
existed the planets had gone out of solar system and everything would
be flying on earth.
Universal Law- Every object attracts and pull each other towards them
due to the gravitation pull that exists on every object (F = G m1m2/d²).
Gravity on Earth- The amount of gravitational pull on earth is 9.8 m/s²
which pulls everything towards centre.
10 Key Facts
G = Universal gravitational constant (6.67 × 10^-11)
Mass = Amount of matter (constant everywhere)
Weight = mg (force due to gravity)
Free fall = All objects same acceleration (9.8 m/s²)
Moon gravity = 1/6th Earth (jump higher)
Buoyancy = Upward force by liquid/gas
Thrust = Force perpendicular to surface
Pressure = Force/Area
Density = Mass/Volume
Relative density = Density of substance/Density of water
6 Exam MCQs
1. F = G ? (a) m1m2/d² ✓ (b) md
2. Earth gravity: (a) 9.8 m/s² ✓ (b) 1.6 m/s²
3. Weight depends on: (a) mass only (b) gravity ✓
4. Moon weight: (a) same (b) 1/6th ✓
5. Buoyant force = ? (a) weight liquid displaced ✓
6. 1 atm = (a) 10^5 Pa ✓ (b) 10^3 Pa
Quick Revision
Trick: Mass(everywhere same) Weight(changes with g)
