Gravity and Universal Gravitation
Learning Objectives
- Students will understand Newton's law of universal gravitation
- Students will calculate gravitational force between objects
- Students will understand why g = 9.8 m/s² at Earth's surface
Core Concepts
- Gravity: attractive force between all masses
- Gravitational force decreases with distance squared
- g varies with location and altitude
Formulas
$$F = G\frac{m_1 m_2}{r^2}$$
Newton's law of universal gravitation
$$g = \frac{GM}{R^2}$$
Gravitational acceleration at planet's surface
$$g = 9.8 \; \text{m/s}^2$$
Standard value at sea level
Interesting Fact
Newton's law of universal gravitation can be tested by measuring the attraction between lab masses
Key Scientist
Henry Cavendish
Experimentally measured the gravitational constant G
Ancient Wisdom
The concept of universal attraction echoes many mystical traditions' view of cosmic interconnection and unity of all existence.
Want to truly master this? Try the interactive lesson!
Start Lesson