Summary
- Free fall occurs whenever an object is acted upon by gravity alone.
- An object in free fall experiences an acceleration due to gravity.
- The acceleration due to gravity…
- is a natural phenomena,
- is represented by the symbol g (italic),
- varies with location,
- is effectively 9.8 m/s2 over the entire surface of the Earth,
- is independent of mass, and
- always points down (in a sense, it's the definition of down)
- The acceleration due to gravity…
- is a natural unit of acceleration,
- is represented by the symbol g (roman),
- is equal to 9.80665 m/s2 by definition,
- is often rounded to 9.8 m/s2 for convenience,
- is sometimes called the "g force" even though it is not a measure of force, and
- does not have a direction (in fact, no unit has a direction)