1. Journal Entry 9 Newton’s Laws of Motion

2. Newton’s First Law of Motion: An object will maintain its velocity (speed & direction) unless acted on by a nonzero net force.
Newton’s first law of motion describes the inertia of an object.
An object’s tendency to maintain its current state of motion is it’s inertia.

3. Newton’s 2nd Law of Motion: The NET FORCE acting on an object is the product of its mass & acceleration.
Fnet = ma
When an object has zero net force acting on it, it is in equilibrium.
Equilibrium has two conditions:
Constant Velocity OR Constant Rest
Both mean ZERO ACCELERATION

4. There are TWO ways to determine the magnitude of the net force: Fnet = ma Fnet = Sum of All forces These two expressions can be set equal to each other: ma = Sum of All Forces
Fnet = ma = F1 + F2 + …

5. Newton’s Third Law: Forces always exist in pairs
Newton’s Third Law: Forces always exist in pairs. For every force, there is a force of equal magnitude in the opposite direction.
Sometimes stated as: For every action force there is an equal and opposite reaction force.
Important: FORCE PAIRS MUST ACT ON DIFFERENT OBJECTS!

6. DO NOT LEAVE THIS SLIDE BLANK!