Free fall is motion in which gravity is the only significant force acting on the object. Close to Earth's surface and when fluid resistance is negligible, the acceleration is approximately constant and directed downward.
All freely falling objects at the same location have the same gravitational acceleration when air resistance is neglected. Mass does not change the free-fall acceleration in this model.
Formula / representation
Free fall can be modelled with the SUVAT equations by assigning the acceleration component according to the chosen positive direction:
- upward positive:
- downward positive:
At the highest point of a vertical launch, momentarily, but is still downward.