Question 1

What is Newton's Law of Universal Gravitation?

Accepted Answer

Newton's Law of Universal Gravitation states that every particle in the universe attracts every other particle with a force F = Gm₁m₂/r², where G is the gravitational constant, m₁ and m₂ are the masses, and r is the distance between their centers. This law explains everything from falling apples to planetary orbits.

Question 2

What is the gravitational constant G?

Accepted Answer

The gravitational constant G = 6.674 × 10⁻¹¹ N·m²/kg² is a fundamental physical constant that determines the strength of gravitational attraction. It was first measured by Henry Cavendish in 1798 using a torsion balance experiment. G is extremely small, which is why gravitational forces are only noticeable when at least one object has enormous mass.

Question 3

Why is gravity so weak compared to other forces?

Accepted Answer

Gravity is roughly 10³⁶ times weaker than the electromagnetic force. The gravitational constant G is extraordinarily small. We notice gravity only because planets, moons, and stars are so massive. At the atomic scale, gravitational forces between particles are utterly negligible compared to electromagnetic forces.

Question 4

How is gravitational acceleration calculated?

Accepted Answer

Gravitational acceleration at a point due to mass m₁ is g = Gm₁/r². For Earth (mass ≈ 5.97 × 10²⁴ kg, radius ≈ 6.37 × 10⁶ m), this gives g ≈ 9.81 m/s². This value decreases with altitude because r increases.

Gravitational Force Calculator (F = Gm₁m₂/r²)

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