Study Guides/Physics/What is the Acceleration of Free Fall
Study Guide · Physics

What is the Acceleration of Free Fall? (Physics)

Drop a ball from a rooftop. It doesn't fall at a constant speed — it speeds up every second. This continuous speeding up is caused by Earth's gravity, and the rate at which it speeds up is a fundamental constant called the Acceleration of Free Fall.

Question (Click to Flip)

Does a heavier object fall faster than a lighter one?

Answer

No! Galileo proved that in the absence of air resistance, all objects fall with the same acceleration (g = 9.8 m/s²) regardless of their mass. A feather and a hammer dropped in a vacuum hit the ground simultaneously.

Card 1 of 1 free previews

Key Facts

On the Moon, the acceleration of free fall is only 1.6 m/s² — about 1/6th of Earth's — which is why astronauts bounce slowly and can jump very high!

Definition

The Acceleration of Free Fall (also called Acceleration due to Gravity, denoted g) is the constant acceleration experienced by any object falling freely under the influence of Earth's gravity alone, with no other forces acting on it (no air resistance).

Value: g = 9.8 m/s² (approximately 10 m/s² for quick calculations)

What does 9.8 m/s² mean?

Every single second an object is in free fall, its downward speed increases by 9.8 meters per second.

  • After 1 second: speed = 9.8 m/s
  • After 2 seconds: speed = 19.6 m/s
  • After 3 seconds: speed = 29.4 m/s

Key Equations of Free Fall

Using kinematic equations with a = g = 9.8 m/s² and initial velocity u = 0:

  • v = gt (final velocity)
  • h = ½gt² (distance fallen)
  • v² = 2gh (velocity after falling height h)

Questions and Answers

Does a heavier object fall faster than a lighter one?+

**No!** Galileo proved that in the absence of air resistance, all objects fall with the same acceleration (g = 9.8 m/s²) regardless of their mass. A feather and a hammer dropped in a vacuum hit the ground simultaneously.

More in Physics

Study Smarter with Shinyu.ai

Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.