Newton's Law of Motion

• Represents the push or pull applied to an object to change its motion or shape.
• Force is a vector quantity, which means it has both magnitude and direction.
• The SI Unit for force is Newton (N).

• Based on Newton's Third Law of Motion, all forces come in pairs.
• Interaction pair is composed of two forces that are in opposite directions and equal in magnitude.

• also called Law of Inertia
• An object at rest will stay at rest and an object at motion with stay in motion at constant velocity unless acted upon by external force.

• also called Law of Acceleration.

$a\propto \frac{F}{m}$

• continues what the first law of motion told us. When a net force is applied, it produces acceleration.
• This law tells us that $F=ma$ that came from $F=\frac{d}{dt}(mv)$
• Deriviation of SI Unit of force:
  • $1N=(1kg)(1m/s^2)$ or
  • $1N=1\frac{kg\cdot m}{s^2}$
• Use $kg$ for mass; weight in $N$.

• For every action, there must be equal and opposite reaction force.
• $Action=-Reaction$