Free Fall

Free fall occurs when an object moves under the sole influence of gravity, without any external force acting on it. When we hold an object, our hand applies an upward force that balances gravity, keeping the object at rest. However, once released, the object falls only due to Earth's gravitational pull, making it a freely falling body.

Characteristics of Free Fall:

• The initial velocity (u) is zero.
• The object accelerates due to gravity (g = 9.8 m/s²).
• In reality, air resistance and buoyant force act on the object, affecting its motion. True free fall happens only in a vacuum.

Equations of Motion for Free Fall:

Using Newton’s equations of motion, where u = 0 and a = g

1. Velocity after time t: v = gt
2. Distance fallen in time t: \[\mathbf{s}={\frac{1}{2}}\mathbf{g}\mathbf{t}^{2}\]
3. Velocity in terms of distance: v² = 2 g s

For an object thrown upwards, acceleration is -g (acting opposite to motion), causing the velocity to decrease until it reaches zero before falling back down.

Galileo’s Experiment on Free Fall:

In 1590, Galileo Galilei demonstrated that objects of different masses fall at the same rate. He dropped two spheres of different masses from the Leaning Tower of Pisa, proving they hit the ground simultaneously in the absence of air resistance. Modern experiments in a vacuum confirmed that a feather and a heavy stone fall at the same rate, proving that gravitational acceleration is the same for all objects, regardless of mass.

When an object of mass $m$ falls freely from a height h, its energy keeps transforming between potential energy (P.E.) and kinetic energy (K.E.). However, the total energy (T.E.) remains constant throughout the fall. Let’s break it down step by step: