AST101H5 Lecture Notes - Lecture 6: Net Force, Fundamental Interaction, Scientific Method
Document Summary
The scientific method is how we gained our understanding of the universe. Gravity is one of the fundamental forces. Newton used it as his 1st law. Net force = the sum of all forces pulling in various directions. If the net force is 0, inertia is constant. A body that is not moving will remain motionless = constant velocity. A moving body"s motion will remain constant at the same speed and in the same direction = constant velocity. Speed is a change of position in some amount of time, such as m/s or km/h. Velocity is a speed in a particular direction. Note: the units, m/s, are still the same, which can cause confusion. If speed remains constant but direction changes, then velocity changes. Newton understood that orbiting objects, such as the moon and earth, have constantly changing velocity because of the changing directions. Newton realized that force causes this changing velocity. The force is gravity for orbiting objects.
