Newton's first law of motion - Forces

Notes:

In this lesson, we will learn:

• Newton's first law of motion
• Inertia
• Explaining physical phenomena using Newton's first law and inertia

Notes:

• Newton's first law of motion can be stated as "if no net force acts on an object, then the velocity of the object does not change."
• Net force is a vector sum of forces acting on an object.
• Newton's first law is also called the law of inertia. Inertia is an idea that originated from Galileo, which says that objects have a tendency to resist changes in their motion:
  • Objects in motion will tend to stay in motion by continuing at their velocity in a straight line, and objects at rest tend to stay at rest.
  • Objects with more mass have "more inertia". It is more difficult to get a more massive object change its velocity by speeding up, slowing down, or changing direction.