When you drop an object, it falls straight to the ground. This movement is called free fall. It happens because Earth pulls everything toward its center. We call this invisible pulling force gravity.

What is Acceleration Due to Gravity?

In a vacuum—a space with no air—every object falls at the same speed regardless of its weight. As an object falls, it gains speed every second. This change in speed is called acceleration. On Earth, this acceleration is constant and is represented by the letter g. Its value is approximately 9.8 meters per second squared (m/s²). This means that every second an object falls, its speed increases by 9.8 meters per second.

Key Formulas for Free Fall

To calculate how an object moves under gravity, we use specific equations. When an object is dropped from rest, its initial velocity (u) is zero. Here are the three main rules:

• Velocity at any time (v): v = g × t (Where 't' is the time taken).
• Distance covered (h): h = 1/2 × g × t² (Where 'h' is the height).
• Final velocity based on height (v²): v² = 2 × g × h.

Real-World Examples of Gravity

Think about a ball falling from a building. If you drop it, gravity pulls it down. If you throw it upwards, gravity slows it down until it stops for a tiny split second at the very top. Then, gravity pulls it back down. This is why a ball thrown into the air always comes back to Earth. Air resistance, or the force of air pushing against a moving object, is why a leaf falls slower than a rock. In real life, air acts like a cushion, but the pull of gravity remains the same for both.

Points to Remember

• Gravity acts downward, so we take the value of 'g' as positive when an object falls.
• If you throw an object upward, gravity acts against the motion, so we take 'g' as negative (-9.8 m/s²).
• At the highest point of an upward throw, the final velocity becomes zero before the object starts falling back down.