1. Acceleration due to gravity

2. Acceleration occurs because an unbalanced force is created
Gravity is an example of an unbalanced force

3. Around 1604 Galileo discovered that acceleration due to gravity is constant.
Acceleration due to gravity describes the motion of an object falling toward a large body, such as a planet
Probably the most important example of constant acceleration

4. In the 1600s Galileo demonstrated that if air resistance is reduced and controlled, all objects fall with the same acceleration
A feather and a hammer will hit the ground at the same time, with the same velocity: if there is no air resistance

5. For short displacments and relatively small velocities ignoring air resistance doesn’t lead to significant error

6. The value of acceleration due to gravity varies slightly at different locations on Earth.
The Canadian average is 9.81m/s2
Formula:
During these calculations we consider [down] to be positive.

7. Example
A baseball is dropped from a height of m at the North Pole. Repeated trials showed that the average time for the baseball to fall from rest was 0.502s. Calculate the acceleration due to gravity at the North Pole. Assume down is positive