1. Acceleration due to Gravity
Free Fall
Acceleration due to Gravity

2. Acceleration Due to Gravity
The acceleration of an object in free fall that results from the effect of Earth’s gravity.
Near the surface of the earth, objects acceleration downward at a rate of 9.8 m/s2
As you move farther from the Earth’s surface, this decreases.
If object is dropped from a stationary postion, the initial velocity is 0 and g = +

3. Air Resistance
Form of friction that prevents objects from falling at the same rate.
Removal of air would result in objects falling at the rate.

4. Objects Launched Upward
Since the object’s initial motion is up, the direction “up” would be positive.
Acceleration due to Gravity = -g
At the highest point, the object has a velocity of 0

5. Sample Problem
An object falls from the top of a building for 1.5 s after starting at rest.
What is it’s velocity?
How tall is the building?
Known
A = -g = -9.8 m/s2
d0 = 0
v0 = 0
d = ?
v = ?