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Newton's Law of Universal Gravitation:
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Newton's Law of Universal Gravitation states that every particle attracts every other particle in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
The calculator uses the gravitational force equation:
Where:
Explanation: The force between two objects increases with their masses and decreases with the square of the distance between them.
Details: This fundamental force governs the motion of planets, stars, and galaxies. It's essential for understanding orbital mechanics, tides, and the large-scale structure of the universe.
Tips: Enter masses in kilograms and distance in meters. All values must be positive numbers. The gravitational constant (G) is fixed at 6.67430 × 10⁻¹¹ N·m²/kg².
Q1: Why is the gravitational force so weak for small objects?
A: The gravitational constant (G) is extremely small (6.674 × 10⁻¹¹), making the force negligible unless at least one mass is very large (like a planet).
Q2: How does this relate to Earth's gravity?
A: Earth's surface gravity (9.8 m/s²) comes from applying this formula with Earth's mass (5.97 × 10²⁴ kg) and radius (6.371 × 10⁶ m).
Q3: Does this formula work for any distance?
A: It works well for most astronomical distances, but at very small scales (quantum level) or very strong fields (near black holes), general relativity is needed.
Q4: Why is the force inversely proportional to distance squared?
A: This "inverse square law" occurs because gravity's influence spreads out over the surface area of an expanding sphere (4πr²).
Q5: How was the gravitational constant measured?
A: Henry Cavendish first measured G in 1798 using a torsion balance experiment with lead spheres.