Contents
Key Stage 4
Meaning
Free fall is when an object accelerates due to only its weight due to gravity.
About Free Fall
- During free fall the only force acting on an object is its weight due to gravity.
- Objects in a gravitational field accelerate at a rate which is the same as the gravitational field strength.
- All objects in free fall will accelerate at the same rate, regardless of their mass or weight. However, objects do not always free fall due to air resistance. For example a feather and a hammer have the same rate of free fall in a vacuum but in an atmosphere air resistance has a greater effect on the feather so they appear to accelerate at different rates.
- Objects on Earth accelerate during free fall at a rate of 9.8m/s/s.
Key Stage 5
Meaning
The acceleration of free fall is the acceleration experienced by an object only under the influence of gravity, typically 9.8m/s² on Earth.
About Free Fall
- Also known as gravitational acceleration.
- It is constant for all objects near the Earth’s surface regardless of their mass.
- Represented by the symbol 'g'.
- In the absence of drag, all objects fall with the same acceleration due to gravity.
- The value of g decreases with altitude and is slightly different at the poles and the equator due to the Earth’s shape.
- Galileo's experiments demonstrated that objects fall at the same rate irrespective of their mass.
- Free fall acceleration is used in various physics equations such as s = ut + 0.5gt² for distance and v = u + gt for final velocity.
Examples
- Objects in a vacuum chamber fall at the same rate regardless of their mass.
- Free fall rides in amusement parks simulate this acceleration.