The obvious answer is wrong
Ask anyone on the street: "If you drop a bowling ball and a feather from the same height, which one hits the ground first?" Almost everyone will say the bowling ball. And on Earth, in normal conditions, they are right.
But the reason they give is almost always wrong. Most people think heavy objects fall faster because they are heavy. That is not how gravity works.
Gravity accelerates all objects at the same rate — 9.8 m/s² — regardless of their mass. The bowling ball and the feather experience the exact same gravitational acceleration. The only reason the feather loses on Earth is air resistance.
The real villain: air resistance
Air resistance is a force that pushes against objects as they move through air. It depends on two things: the object's surface area and its speed. A feather has a large surface area relative to its weight, so air resistance affects it enormously. A bowling ball has a small surface area relative to its weight, so air barely slows it down.
This is why the feather floats gently while the ball plummets. It is not gravity treating them differently. It is air treating them differently.
Proof: it actually happened on the Moon
In 1971, Apollo 15 astronaut David Scott stood on the surface of the Moon and dropped a hammer and a feather at the same time. The Moon has no atmosphere, so there is no air resistance. Both objects hit the lunar surface at exactly the same moment.
It was one of the most elegant physics demonstrations ever performed — and it confirmed what Galileo had argued over 400 years earlier: in the absence of air, all objects fall at the same rate, regardless of mass.
Gravity pulls harder on heavier objects — but heavier objects also require more force to accelerate. These two effects cancel out perfectly. The result: same acceleration for everything. This is why the formula v = g × t does not include mass.
How fast does a falling object go?
If you ignore air resistance, calculating the speed of a falling object is surprisingly simple. Velocity equals gravitational acceleration multiplied by time:
That is it. No mass in the equation. Whether you drop a marble or a truck, after the same amount of time in free fall, they are travelling at the same speed.
| Time falling | Speed | That is like... |
|---|---|---|
| 1 second | 9.8 m/s | A fast cyclist |
| 2 seconds | 19.6 m/s | A car on a highway |
| 3 seconds | 29.4 m/s | Over 100 km/h |
| 5 seconds | 49.0 m/s | A speeding Formula 1 car |
| 10 seconds | 98.0 m/s | Faster than most planes take off |
In the real world, air resistance eventually balances gravity and the object stops accelerating. That maximum speed is called terminal velocity. For a skydiver, it is about 55 m/s. For a bowling ball, much higher. For a feather, just a few meters per second.
The Physiworld lesson walks you through v = g × t step by step, with a worked example and a timed calculation challenge where you compute the final velocity of a falling ball.
What about terminal velocity?
Terminal velocity is not a fixed number — it depends on the object. A skydiver in a spread-eagle position has a terminal velocity of about 55 m/s. Tuck into a head-down dive and it rises to about 90 m/s. A bowling ball dropped from high enough would eventually reach about 70 m/s.
A feather? Its terminal velocity is roughly 0.5 m/s. That is why it floats gently — air resistance matches gravity almost immediately.
But in a vacuum, there is no terminal velocity. Objects just keep accelerating forever. After 10 seconds, any object would be travelling at 98 m/s. After a minute, 588 m/s. There is no limit because there is nothing pushing back.
Test your understanding
4 questions based on what you just read.
Why this matters
The bowling ball vs feather question is not just a fun thought experiment. It reveals a deep truth about gravity: acceleration does not depend on mass. This principle is the foundation of everything from how astronauts float to what would happen if gravity disappeared.
The formula v = g × t is your first tool for putting numbers to free fall. On Physiworld, the lesson walks you through worked examples and a calculation challenge using this exact formula — step by step, with instant feedback.
All objects fall at the same rate in a vacuum — 9.8 m/s² on Earth — regardless of mass. Air resistance is the only reason heavy and light objects behave differently. The formula v = g × t calculates how fast a falling object is moving at any moment, and mass is not part of it.
Learn when to ignore air resistance, how to calculate final velocity in free fall, and test yourself with timed calculation problems. Earn XP along the way.
The Gravity section covers Newton's Law, weight calculations, free fall, and escape velocity across 5 interactive lessons with simulations and challenges.