Which will fall faster?

Question

Do both heavy & light objects fall at same velocity? Isn't heavier objects have greater pull, according to law of gravitation?

Answer 1

Objects fall at a same rate; that means all objects close to the surface of the Earth fall with constant acceleration (g=9.8 m/s^2) NOT velocity.

Here are few important things to consider :

1. If the only force acting on the falling object is gravity and the drag force is negligible then using Newton's second law F=ma, you'll have $$\text{Force of gravity} = m a \to mg=ma$$ and as you can see from this equation $m$(mass) will cancel from both sides of the equation and you're left with $a=g$. Therefore, all objects should fall with the same acceleration g= 9.81 m/s$^2$.

2. If the drag force is not negligible then you will have $$mg-D=ma,$$ where $D$ is your drag. Then depending on strength of the drag force objects can fall at different rates.

3. $g$ can vary from place to place. In general g= 9.80621 -0.026$\cos(2\phi ) - 0.003 h$ m/s$^2$ where $\phi$ is geographical latitude and $h$ is elevation above sea level.

Answer 2

Yes, heavier objects feel a larger pull from gravity.

But heavier objects are also harder to accelerate.

These two effects balance each other out - objects of double mass, feel a doubled pull from gravity but also resist this pull twice as much (due to Newton's 2nd law). In the end it balances out and the result is always a fall with $9.82\;\mathrm{m/s^2}$.