Newtons St 1 Law An object at rest

Newton’s St 1 Law An object at rest remains at rest, and an object in motion remains in motion with constant velocity ( same speed and direction ) unless acted on by a net external force

Newton’s Second Law n n Any change in the original state of motion is caused by a net force That change in motion ( acceleration ) is directly proportional to the force if the mass is constant If the force is constant then the acceleration is inversely proportional to the mass If the acceleration is constant the force is directly proportional to the mass.

Newton’s Third Law n If two objects interact, the force exerted on object 1 by object 2 is equal in magnitude but opposite in direction to the force exerted on object 2 by object 1 unless acted on by a net external force n The action force is is equal in magnitude to the reaction force and opposite in direction. n F = ma ( Think about what happens when a is really large or when m is really large )

Implications n Forces always occur in pairs! n The action force is is equal in magnitude to the reaction force. n F = ma ( Think about what happens when a is really large or when m is really large )

What does this mean Newton’s First Law – a=0 n Newton’s Second Law a 0, one body (object) n Newton’s third law two bodies interacting n