1. The Drag Force and Terminal Speed
When an object moves through a liquid or a gas (such as air), the fluid resists the motion of the object and the resistive force or drag force depends or the velocity of the object.

2. GRAVITATION Isaac Newton
Isaac Newton showed that the interaction (force) makes an apple fall is the same interaction that keeps moon in its orbit
The interaction gravitation

3. Newton’s Law of Universal Gravitation: Every particle in the universe attracts every other particle with a force that is proportional to the product of the masses and inversely proportional to the square of the distance between them. This force acts along the line joining to particles.
Newton’s Law of Universal Gravitation
Measured by Cavendish

4. Cavendish’s Apparatus
Q: Can you attract another person gravitationally?

5. Principle of Superposition

6. Gravitation near Earth’s surface