Universal Gravitational Law

The gravitational attraction between two objects depends upon the mass of the objects and the distance between them. This relationship is often called the "Universal Law of Gravitation" and can be expressed as:

$$F = k_G \frac{m_1 m_2}{r^2}$$

Where:

• F = gravitational force (N)
• k_G = 6.668×10⁻¹¹ (Nm²/kg²) = Universal Gravitation Constant
• m₁, m₂ = mass of objects (kg)
• r = distance between objects (m)

Example

The gravitational force acting on a 70 kg person on Earth's surface (6.37×10⁶ m from Earth's center):

• F = (6.668×10⁻¹¹) × (5.98×10²⁴) × (70) / (6.37×10⁶)²
• F = 688.1 N