Forces+&+Newton's+Laws

Newton's Laws 1. An object at rest remains at rest, and an object in motion continues with a constant velocity unless the object experiences a net external force. inertia- is the tendency of an object not to accelerate A bullets speed does not decrease throughout the whole flight of the bullet. A car will not move unless a force(the propultion of the engine) moves it.

2. Force is proportional to mass and acceleration-this is speeding up motion...one person will not be able to move a car as fast as three people because with three people there is more weight behind it giving it more acceleration. Net Force definition 1.-resultant force of all the forces acting on it definition 2.- force diagram example Mass is how much space you take up and Weight is how much gravity is pulling down on you. Pushing a light guy on the moon will be easier than pushing a fat guy on the moon just like the earth.

3. for every action there is an equal and opposite reaction definition-the air shooting out of a baloon propells it forward normal force-a force that acts on a surface in a direction perpendicular to the surface action and reaction pairs-when you shoot a gun there is a kick because of the sudden forward motion of the bullet Friction-is the force resisting horizontal motion coefficient of friction-is the ratio of friction between two objects and the forces pushing them together two things friction depends on-the surfaces and the amount of force used to push the objects together kinetic vs. static-kinetic is how much force needed to keep it going and static is how much force is needed to start the motion