1. Dynamics: The Why of Motion Inertia, Force, and Newton’s Laws

2. Inertia  The property of an object to persist in its current state of rest or uniform motion.  Generally refer to frames of reference fixed on the earth (since earth rotates, technically the frame is accelerating)  Two frames of reference- inertial and non inertial (or accelerating)

3. Forces  Any kind of push or pull e.g. pushing on a stroller, pulling on a rope, kicking a ball, etc  Forces can act on an object and the result can be no net motion.  An object either at rest or travelling at constant velocity is in equilibrium

4. Forces  Can be contact where there is physical contact between two objects e.g. shooting a basketball, pulling on the handle of a wagon  Can be action-at a-distance forces which do not have physical contact e.g. the earth pulls on the moon, electrical charges attract or repel, magnets attract or repel

5. Forces: 4 Fundamental Types  Strong Nuclear  Weak Nuclear  Electromagnetic  Gravitational

6. Newton’s First Law: Law of Inertia  An object at rest will remain at rest and an object in motion will continue in motion with a constant velocity (i.e. in a straight line) unless it experiences a net external force

7. Newton’s Second Law: Law of Acceleration  The acceleration of an object is directly proportional to the resultant force acting on it (in the same direction) and is inversely proportional to the mass of the object

8. Newton’s Third Law: Law of Interaction  If two objects interact, then the force on object 1 by object 2 is equal and opposite to the force exerted on object 2 by object 1  F 1 2 = - F 2 1