The Nature of Force Newton’s Laws

What is a Force? A force is a push or a pull. When one object pushes or pulls another object, you say that the first object is exerting a force on the second object. Forces are described not only by how strong they are, but also by the direction in which they act.

Forces In order to create motion (or stop it ) you must have an unbalanced force. Balanced forces cancel each other out. (No motion) When two forces act in the same direction they add together. (creating an unbalanced force)

When forces act in opposite directions, an one is larger than the other, the overall force is in the direction of the greater force.

Newton’s Laws Isaac Newton was an English mathematician who discovered the three basic laws of motion. His first law: An object at rest will stay at rest, and an object in motion will stay in motion unless acted on by an unbalanced force. AKA: Law of Inertia Inertia: the tendency of an object to resist change in its motion.

Newton’s First Law The amount of inertia an object has, depends on its mass. The greater the mass, the greater its inertia.                                                                                              A lot of inertia! Very little inertia

F =Mass x Acceleration Newton’s Second Law Newton’s second law of motion states that The net force on an object is a product of its acceleration and its mass. Or, an easier way to remember this is: F =Mass x Acceleration

Newton’s Second Law F = M*A Let’s assume that the wheels of a 5-kg car apply 10 N of force. The net force would equal 10 Newtons. What is the acceleration of the car? Mass = 5 kg

Newton’s Third Law Newton’s third law states that: For every action, there is an equal and opposite reaction.

Action-Reaction

Recap! 1. An object in motion will stay in motion, or an object at rest will stay at rest unless acted on by an unbalanced force. 2. Force = Mass x Acceleration 3. For every action, there is an equal and opposite reaction.