1	Describing Motion Newton’s Laws
2	First we need to define the word FORCE: The cause of motion (what causes objects to move) Two types of forces Pushes Pulls
3	Forces are measured in Newtons SI unit of force Symbol: N Measured by using a spring scale
4	Forces may be balanced or unbalanced Balanced forces – all forces acting on an object are equal There is NO MOTION Unbalanced forces – one or more forces acting on an object are stronger than others There is MOTION A NET FORCE
5	Newton’s Laws First Law – Inertia Second Law – Acceleration, Force & Mass Third Law – Action-Reaction
6	First Law Inertia An object at rest [not moving] remains at rest unless acted on by a force [push or pull] An object in motion remains in motion unless acted on by a force [push or pull]
7	First Law Inertia & Mass Mass is the amount of matter in an object The more MASS an object has, the more INERTIA the object has. Bigger objects are harder to start & stop
8	Second Law Acceleration & Mass Definitions Acceleration is a change in velocity [speed or direction] Mass is the amount of matter in an object
9	Second Law Acceleration & Force The more force placed on an object, the more it will accelerate [change its motion] Acceleration & Mass The more mass [or inertia] an object has, the more force it takes to accelerate the object
10	Third Law Action – Reaction Forces are always produced in pairs with opposite directions & equal strengths For every force there is an equal and opposite force
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