Newton’s 1st Law – Inertia

Isaac Newton - Describes motion with 3 basic laws An object in motion will stay in motion. An object at rest will stay at rest. Unless acted upon by another force. 2) The greater the force the greater the acceleration. 3) For every action there is an equal and opposite reaction.

Newton’s first law relates force and motion. “An object in motion will stay in motion. An object at rest will stay at rest. Unless acted upon by another force.” – Newton’s First Law The key points of Newton’s first law are: Objects with no net force acting on them have either constant velocity or zero velocity. Force is needed to start motion or change motion. Inertia is the resistance of an object to change its motion. Inertia is directly proportional to the object’s mass. Mass is the measure of inertia.

pull push A force is a push or a pull Force in physics is defined as “a push or a pull”. pull push

A force is a push or a pull Force in physics is defined as “a push or a pull”. Some forces: - require contact between objects, such as friction, and - act at a distance, such as gravity and electromagnetic forces.

A force is a push or a pull Force in physics is defined as “a push or a pull”. Some forces: - require contact between objects, such as friction, and - act at a distance, such as gravity and electromagnetic forces. Force contains magnitude (strength) and direction. Net force is the total force that affects an object when multiple forces are combined. The net force depends on both the direction and the size of the individual forces.

Combining forces in the same direction. Measuring Net Force 1) Identify forces to combine. 2) Put tail of second force arrow to tip of first force arrow. Maintain length (size) and direction. 3) Measure from tail of first force arrow to tip of second force arrow. Combining forces in the same direction. Net Force

Combining forces in opposite direction. Measuring Net Force 1) Identify forces to combine. 2) Put tail of second force arrow to tip of first force arrow. Maintain length (size) and direction. 3) Measure from tail of first force arrow to tip of second force arrow. Combining forces in opposite direction. Net Force