Newton's Law of Motion (PDF)

NEWTON’S LAW OF MOTION : 1 ST LAW OF INERTIA Every object continues in its state of rest or of uniform speed in a straight line (constant velocity) unless a net force acts on it. (influenced by Galileo’s findings)  LAW OF INERTIA Inertia is the t...

NEWTON’S LAW OF MOTION : 1 ST LAW OF INERTIA Every object continues in its state of rest or of uniform speed in a straight line (constant velocity) unless a net force acts on it. (influenced by Galileo’s findings)  LAW OF INERTIA Inertia is the tendency of an object to resist changes in its velocity: whether it’s in motion or motionless. These basketballs will not move unless acted on by an unbalanced force. Why then do we observe every day objects in motion slowing down and becoming motionless seemingly without an outside force? It’s a force we sometimes cannot see – friction.  LAW OF INERTIA Old thinking: Continual forces are needed to maintain motion. New thinking: A force causes an object to move, and it will continue to move in such a way until another force acts on it.  NET FORCE Net Force – the combination of all forces that act on an object Net force is needed to change an object’s state of motion. How is net force different from force? Newton = scientific unit of force AN EXAMPLE OF NET FORCE Shooting a basketball force of gravity air friction pushing force  Net Force – the combination of all forces that act on an object Vector Quantities 5N 5N 10 N (to the right) _____________________ 10N 10N 0N _____________________ 15N 5N 10 N (to the left) _____________________