How do 2 objects of different weights fall and touch the ground at the same speed and time?


Imagine 2 objects, 1 is a 50kg dumbbell and 1 is a 1g feather, how is it possible that they will fall and touch the ground at the same speed and time assuming they are dropped from the same height?

I must be understanding this completely wrong.

Edit: I definitely understood it completely wrong because I did not know it only applied to objects in space. That makes much more sense.

In: 0

Gravity pulls *on mass*. Something twice as heavy is pulled twice as hard, but is also twice as hard to move.

These two effects cancel perfectly, however other things like air getting in the way may unbalance the rates and cause one to fall faster.

First of all, this is only in a vacuum, where air resistance does not exist. Typically it still doesn’t matter *too much*, but with the example of a feather, it definitely matters.

The reason everything accelerates equally, is because for every “extra pull” they get from gravity (for being more massive), they have an equal “extra resistance to acceleration”, which we call inertia.

It’s possible because acceleration due to gravity close to Earth is mass independent. This can be derived from Newton’s laws, basically the extra force necessary to accelerate a heavy object is exactly cancelled out by the fact that gravity pulls harder on heavier objects.

But your intuition isn’t wrong in the example you gave. A feather will not always hit the ground at the same time as the weight. But it’s not because gravity is working differently on them, it’s because there is *air resistance* that significantly slows down the feather, but doesn’t really affect the dumbbell.

This phenomenon only occurs in a space completely devoid of air. When released in a vacuum with no air resistance they will fall at the same rate because gravity acts on the two bodies uniformly no matter the weight difference. The reason this cannot occur in an open air environment is because the force of the air resistance on the feather from all direction is enough to counteract gravity. The bowling ball, on the other hand, with a higher weight class can now through the air resistance forces.

I’m likely wrong on this, so someone please correct me, but:

Gravity isn’t a force and isn’t pulling. They are traveling straight through time and space. If those objects were floating in space, would you expect them to orbit differently given same starting variables?