Forces+&+Newton's+Laws

=1st Law= -When no net force is applied to an object the object's acceleration is zero.

Net Force - Sum of all forces acting on an object; when this is zero an object's motion will not change, Newton's first law. Inertia - Tendency of an object to resist change in speed or direction. Inertia depends on an objects mass; the larger the mass the harder it is to accelerate.

Examples: When you push a cup of water the water pushes up against the side you pushed from; this is because of waters inertia. However, when the cup stops moving the water flings to the other side of the cup; this is because no force is slowing it down.

=2nd Law= -The acceleration of an object is determined by its mass and the net force acting on it.

Therefore, net force = mass * acceleration

NOTE: An objects weight is not it's mass. Weight is the force you output due to gravity; gravity changes depending on which planet you're on. Therefore you're weight will be different on the moon than it is on earth; you're mass will not.

=3rd Law= -For every action, there is an equal and opposite reaction.

Ex: A bowling ball hits another ball, the first ball stops and the second ball starts moving just as fast as the first ball was.

Normal Force - Force that acts perpendicular (away from) a surface. Action Reaction Pairs - The two objects effected by an action and it's equal and opposite reaction.

Friction - Force opposing movment usually created by objects rubbing together. (Object sliding on a table) Coefficient of Friction - A value that represents the amount of friction two surfaces have.

Friction depends on weather or not an object is stationary: Static Friction - The friction applied when an object is at rest. (Stationary or at Constant Velocity) Kinetic Friction - The friction applied when an object is not at rest. (Accelerating)