Acceleration: The rate of change in velocity (Vector quantity)

• Acceleration has both magnitude and direction like velocity

• * IF the velocity and acceleration of an object are pointing towards the same direction, the object will speed up

• * IF the velocity and acceleration of an object are pointing away from each other, the object will slow down

• * Just like velocity, acceleration can also vary over time, which means that an acceleration can either be constant or changing rate of acceleration 

Constant Acceleration:When the rate of change in velocity is constant

• In most questions and problems, acceleration will be constant (e.g. an object rolling down a steady incline)

• * When acceleration is constant, one of the four following equations (directly below) can be used to calculate displacement (Δx), initial (vi), final velocity (vf), acceleration (a), and time (t) depending on the already given information

Free Fall: When an objects falls with a constant acceleration with gravity being the only force that acts on it

• * Near the surface of the Earth, all objects (when freefalling) falls with a constant, downward acceleration due to gravity (g) of 9.8 m/s^2. Thus, g = 9.8 m/s^2

• * NO MATTER the position, velocity, or the elapsed time, if no other forces other than gravity is acting on the falling object, it will always be in free fall with a downard acceleration of g (or 9.8 m/s^2)