Gravity

• Quantified by Isaac Newton
• Universal attraction among all bodies everywhere
• Gravitational attraction between two objects:
  • $F_{gravity} = G \frac{M_1M_2}{R^2}$
    • $F_{gravity}$ is the force of gravity between two objects
    • $M_1$ and $M_2$ are the masses of two objects
    • $R$ is the separation of those objects
    • $G$ is the universal gravitational constant

Universal Gravitational Constant

• $6.67 \times 10^{-11} m^3 / (kg s^2)$

Escape Velocity

• Velocity needed to escape from gravitational pull of an object
• Escaping an orbit of an object
• Formula:
  • $v_{escape} = \sqrt{\frac{2GM}{R}}$

Physics Astronomy