What do you mean by free fall?

Free fall means an object is falling only under gravity with no air resistance. In free fall, the only force acting on the object is gravitational force. This is an ideal concept used to simplify motion. Near Earth’s surface, such motion has a nearly constant acceleration, denoted by g (about 9.8 m/s²). 

In real life, air resistance reduces acceleration and changes the motion, but many exam problems assume perfect free fall.

Core points

• Force: Only gravity acts.
• Acceleration: Constant and equal to g, downward.
• Velocity: Increases linearly with time while falling.
• Equations:v = u + gt, s = ut + ½gt², v² = u² + 2gs (choose downward as positive).

Examples and notes

• Objects dropped in a vacuum chamber undergo true free fall.
• Astronauts in orbit experience weightlessness because both they and their spacecraft are in continuous free fall around Earth.
• Terminal velocity is not part of free fall; it appears when air resistance balances weight, making net force zero.