Do heavier objects fall faster?

Rebelius said:
surely if everything was in a huge vacuum, the apple would fall towards the earth faster because the gravitational pull of the apple on the earth is greater than the gravitational pull of the feather.

but you're not going to notice.
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No, it does not matter about the mass.

F=ma

If you use a as 9.81 which is the acceleration on a mass towards the Earths surface you will find that all objects will move towards the Earth at the same velocity. However some will have a greater resultant force due to their greater mass.
 
Assuming no air resistance, any object on Earth when dropped will accelerate at ~9.81m/s^2 or 1G. The experiment was done on one of the Apollo missions during a lunar EVA - an astronaut dropped a feather and a hammer I believe, they fell at exactly the same rate.

***edit***

Beaten multiple times. I've got to stop multi-tasking :)
 
DunK1 said:
"Subsequently, all objects free fall at the same rate of acceleration, regardless of their mass."
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Yeah, but the original question is "It's to do with mass though isn't it". Which yeah, it is :D (F = ma ;) )
 
I recon if you had a giant empty universe, and only had the earth and an apple, and another giant empty universe, with only the earth and the moon, and in each universe you set them the same distance apart and released them, the moon and earth would collide sooner than the apple and the earth.
 
Blinkz said:
Like I said guys this is all a theoretical situation, so no air resistance or anything. The acceleration between the objects is relative to each other, not from another observation, if that makes sense.

Any actual proof to the answer would be great!
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So you are interested in how two objects accellerate towards each other, not how earth's mavity affect them?

In this case, think about if a ball was dropped from a height of 1m, the ball would move almost the entire metre, and the earth would barely move. This is due to Newtons law wherby the greater the mass an object has, the greater its gravitational pull.
 
Rebelius said:
I recon if you had a giant empty universe, and only had the earth and an apple, and another giant empty universe, with only the earth and the moon, and in each universe you set them the same distance apart and released them, the moon and earth would collide sooner than the apple and the earth.
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Yeah but that's because the moon would have a higher gravitational force than the apple hence why it would happen.

Relatively speaking, on earth, heavy and light objects fall at the same acceleration and thus speed, neglecting wind resistance of course.
 
Rebelius said:
I recon if you had a giant empty universe, and only had the earth and an apple, and another giant empty universe, with only the earth and the moon, and in each universe you set them the same distance apart and released them, the moon and earth would collide sooner than the apple and the earth.
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Yes they would. THe gravitational pull caused by the earth would be the same in both counts, but their would be a greater gravitational pull by the moon (as in pulling the earth towards the moon).
 
sven256 said:
They do not fall at the same speed

They accelerate at the same speed but the terminal velocity's may be different
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Terminal velocity doesn't exist when there is no air resistance. It is caused by the upwards force of air resistance equalling the the downwards force of the object, therefore giving a maximum speed.
 
Rebelius said:
I recon if you had a giant empty universe, and only had the earth and an apple, and another giant empty universe, with only the earth and the moon, and in each universe you set them the same distance apart and released them, the moon and earth would collide sooner than the apple and the earth.
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That's a "reckon" not backed up with any knowledge or maths, can you elaborate?

sven256 said:
They do not fall at the same speed

They accelerate at the same speed but the terminal velocity's may be different
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Terminal velocity is only a term that applies when air/gas is present.
 
the attractive force depends on the mass of BOTH objects.

F= GMm/r^2 - force of attraction = Gravitational constant (6.67300 × 10^-11 m^3 kg^-1 s^-2) * Mass of bigger object (Earth - Kg) * Mass of smaller object (moon or apple - Kg) / Separation squared (m^2)
 
Rebelius said:
I recon if you had a giant empty universe, and only had the earth and an apple, and another giant empty universe, with only the earth and the moon, and in each universe you set them the same distance apart and released them, the moon and earth would collide sooner than the apple and the earth.
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yes but the earth and the moon have more mass so even though the force is inceased, the acceleration will not change due to the masses increasing.

I think the pertinent bit of information that is missing is to whether the gravitational force increases proportionally to the mass, if it does then they will fall at the same rate, if the force increases faster then the mass increases then the heavier mass will fall faster.....
 
Rebelius said:
the attractive force depends on the mass of BOTH objects.

F= GMm/r^2 - force of attraction = Gravitational constant (6.67300 × 10^-11 m^3 kg^-1 s^-2) * Mass of bigger object (Earth - Kg) * Mass of smaller object (moon or apple - Kg) / Separation squared (m^2)
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Already said ;)

It does mean that the smaller object moves faster to the bigger object than the bigger object does to the small. Ie the Earth hardly moves when an apple falls to its surface but the apple moves a tremendous distance in comparison.
 
MasterMike said:
That's a "reckon" not backed up with any knowledge or maths, can you elaborate?
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I think he's wrong. The relevent formula is F=GMm/r^2. In this case r and one of the Ms is the same so they are irrelevent. The resultant force would be different, but since the moon is more massive than an apple, it would take more force to move it with the same acceleration.

edit- similar stuff already said, never mind.
 
Didn't Einstein (I think) test this theory by dropping two objects of different weight off the tower of Piza and it turned out they both hit the Earth at the same time?
 
Abyss said:
Terminal velocity doesn't exist when there is no air resistance. It is caused by the upwards force of air resistance equalling the the downwards force of the object, therefore giving a maximum speed.
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yes my bad should have just though of joe Kittinger :o
 
The last time I did physics was A-level, I got a B, but have done pretty much nothing since. I apologise if I'm missing something here.

We have an object weighing 10000 kg, and an object weighing 100 kg. I'm ignoring units for the sake of simplicity. To get the force f acting between them due to mavity,

f = 6.673 x 10000 x 100 / 100000^2 = 0.0006673

Now, a scenario where we have an object weighing 10000 kg, and one weighing 1 kg. Same again ...

f = 6.673 x 10000 x 1 / 100000^2 = 0.000006673

Now, using the equation f = ma, we get

f = ma;

a = f/m


so: for object 100, a = 0.0006673 / 100 = 0.000006673
for object 1, a = 0.00000673/ 1 = 0.000006673, or exactly the same acceleration for both objects.

This is horrifically simple and likely wrong. Could someone a little more savvy elaborate on this a bit?
 
G-MAN2004 said:
Didn't Einstein (I think) test this theory by dropping two objects of different weight off the tower of Piza and it turned out they both hit the Earth at the same time?
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that was galileo, and that was on the earth, not in a vacuum.
 
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