An object falling without any air resistance under the influence of gravitational force is said to be in free-fall. For free-falling bodies, the acceleration due to gravity is constant, irrespective of their mass. Free-fall is experienced not only by objects falling downward, but also by all objects whose motion is influenced by gravitational force alone. The dynamics of free-fall motion can be calculated using kinematic equations of motion, since free-fall acceleration is constant.

The acceleration experienced by all objects in free-fall is constant; therefore, any two objects dropped from the same height and location on the Earth will fall to the ground at the same speed, provided that the air resistance is neglected. Similarly, if two objects are dropped in succession, then the time required for them to reach the ground will be the same. However, the velocity of the object dropped first will always be greater than the velocity of the object dropped later.

Some real-life examples of free-fall include:

1. Skydiving and bungee jumping
2. A meteoroid accelerating toward the Earth's center
3. A spacecraft in the Earth's orbit
4. The projectile motion of an object in 2-dimensional space

This text is adapted from Openstax, University Physics Volume 1, Section 3.5: Free-fall.