If two objects have the same size and shape, the force applied by air resistance will be the same. However, if two objects have different mass, that same force will result in different acceleration.
The acceleration will be 1G minus drag. The Earth is sufficiently larger than anything one would drop off a tower so the weight of the dropped thing doesn’t matter at all
How does your model of the universe explain the hammer and feather dropped on the moon by Apollo 15’s David Scott landed at the same time?
Ed. There is an effect of buoyancy that will make denser things fall faster. It becomes noticeable in distances where the dropped items reach terminal velocity or on more dense media where buoyancy is more significant.
In air over short distances buoyancy is negligible, in vacuum there is none
Buoyancy is functionally irrelevant here. Buoyancy in air effectively subtracts 1.3kg per cubic meter of each substance: The mass of the volume of air displaced by the object.
The part you are not understanding: Drag applies the same force to both objects. Gravity applies the same acceleration to each object.
The Earth is sufficiently larger than anything one would drop off a tower that the weight of the dropped thing doesn’t matter at all
F=ma.
Two items of the same shape will have the same amount of air resistance. If they have significantly different masses, the two object experience commensurately different accelerations (or reduction in acceleration), even if the force is the same.
If you take a balloon full of tetrahexofluroride (a gas 6x the density of air) and a chunk of iron the exact same size and shape and throw them off a building, I guarantee the iron chunk will hit first.
How does your model of the universe explain the hammer and feather dropped on the moon by Apollo 15’s David Scott landed at the same time?
It’s called a vacuum, which is famous for not having air resistance. Y’know, the thing we’re talking about?
To perform the experiment properly on Earth where there is air resistance, you need to pick a shape and range of masses that minimize the effect of air resistance
Read their claim again: they are specifically describing the effect of air resistance. Their claim is perfectly consistent with the lunar feather/hammer experiment.
Their problem was that they weren’t able to say why, and no one replying to me was able to do more than say they’re right, I’m wrong. See my edit. I added a correction after looking up drag equations for myself and finding that buoyancy was a factor
Two items of the same shape will have the same amount of air resistance. If they have significantly different masses, the two object experience commensurately different accelerations (or reduction in acceleration), even if the force is the same.
The “same force” they are talking about is drag. The two objects are the same size and shape. At the same velocity, drag affects them both equally, applying an equal, upward force against both objects.
Gravity (in a vacuum) accelerates both objects equally. But they have differing masses. F=MA. F/M = A. A is equal for both objects. Because acceleration is equal, the “force” on each object is not: the force must be proportional to its mass: The high mass object must be experiencing high force; the low-mass object must be experiencing low force.
Subtract the “same force” of drag from the downward force on both objects, and the net force on each object is no longer proportional to the mass of each object. Consequently, the high-mass object accelerates in atmosphere faster than the low-mass object. The high-mass object has a higher terminal velocity; the low-mass object has a lower terminal velocity.
For the purposes of this experiment, buoyancy is functionally irrelevant. The effect of buoyancy is to subtract a fixed mass from each object: A mass equivalent to the mass of air displaced by the object. Effectively, buoyancy slightly reduces the density of both objects. The actual difference in the densities of the two objects is far greater than the slight change due to buoyancy in air, so buoyancy is not a significant factor.
While that is true, two properly selected objects (such as the ones mentioned above) can reduce the effect of air resistance to levels negligible to human perception, demonstrating that heavier objects do not intrinsically fall faster.
Not at all. Our air is made up of physical objects (molecules of oxygen and nitrogen, mostly). Things with more mass, more quickly knock those out of the way.
For a demonstration you can see and more easily wrap your head around, take something just barely heavier than water, and a similarly sized heavy rock and drop them in a pool. You’ll see how much quicker the rock gets to the bottom, because it displaces the water so much faster. Our atmosphere is the exact same.
It seems maybe you’re actually misunderstanding. As I mentioned above, both you and the other commenter are certainly correct that the surrounding atmosphere (water in your case) exerts force on the objects as they fall, with varying effects depending on object density. However, if you take two objects that have vastly more density than the water (let’s say a big tungsten rod and another tungsten rod that has a hollow core), they will drop at approximately the same rate in the water even if their density vs each other varies. The greater the difference of their density versus the density of the medium, the less the effect of the medium. Is there still technically an effect? Sure, but that effect is negligible from a human perceptual perspective.
I understand what you’re saying (call it like a 10" 100 pound tungsten ball vs a 5" 50 pound tungsten ball) but your reasoning and logic of being essentially the same are just silly and the math that would dictate when each would land in atmosphere would still line up perfectly (which would be that the heaviest one will hit first). even if it were a 10,000 pound ball and a 5,000 pound ball.
If two objects have the same size and shape, the force applied by air resistance will be the same. However, if two objects have different mass, that same force will result in different acceleration.
So change the shape, a long copper rod and clump of coal.
If you do that then they definitely won’t fall the same.
The acceleration will be 1G minus drag. The Earth is sufficiently larger than anything one would drop off a tower so the weight of the dropped thing doesn’t matter at all
How does your model of the universe explain the hammer and feather dropped on the moon by Apollo 15’s David Scott landed at the same time?
Ed. There is an effect of buoyancy that will make denser things fall faster. It becomes noticeable in distances where the dropped items reach terminal velocity or on more dense media where buoyancy is more significant.
In air over short distances buoyancy is negligible, in vacuum there is none
On Earth, this is the part that makes it so that objects do not fall at the same speed.
This is the type of experiment they could not do 2000 years ago.
That is incorrect. Drag affects both equally. The difference is caused by buoyancy, less dense objects feel more buoyancy
Drag doesn’t exist in a vacuum.
Buoyancy is functionally irrelevant here. Buoyancy in air effectively subtracts 1.3kg per cubic meter of each substance: The mass of the volume of air displaced by the object.
The part you are not understanding: Drag applies the same force to both objects. Gravity applies the same acceleration to each object.
Thanks that does make sense
If F is the same but m is different, what happens to a?
F=ma.
Two items of the same shape will have the same amount of air resistance. If they have significantly different masses, the two object experience commensurately different accelerations (or reduction in acceleration), even if the force is the same.
If you take a balloon full of tetrahexofluroride (a gas 6x the density of air) and a chunk of iron the exact same size and shape and throw them off a building, I guarantee the iron chunk will hit first.
It’s called a vacuum, which is famous for not having air resistance. Y’know, the thing we’re talking about?
To perform the experiment properly on Earth where there is air resistance, you need to pick a shape and range of masses that minimize the effect of air resistance
You are wrong. Falling in a medium is slowed by buoyancy and drag
F=ma has nothing to do with it
Motherfucker, do you seriously not understand that buoyancy and drag are forces?!?!
Sit yo’ Dunning-Kruger ass down
Valid crashout. 🤣
https://en.wikipedia.org/wiki/Dunning–Kruger_effect
Without the m as the browser will decide for itself if it needs the mobile version.
Read their claim again: they are specifically describing the effect of air resistance. Their claim is perfectly consistent with the lunar feather/hammer experiment.
Their problem was that they weren’t able to say why, and no one replying to me was able to do more than say they’re right, I’m wrong. See my edit. I added a correction after looking up drag equations for myself and finding that buoyancy was a factor
Also, thank you for replying civilly
They did. You didn’t understand what they said.
The “same force” they are talking about is drag. The two objects are the same size and shape. At the same velocity, drag affects them both equally, applying an equal, upward force against both objects.
Gravity (in a vacuum) accelerates both objects equally. But they have differing masses. F=MA. F/M = A. A is equal for both objects. Because acceleration is equal, the “force” on each object is not: the force must be proportional to its mass: The high mass object must be experiencing high force; the low-mass object must be experiencing low force.
Subtract the “same force” of drag from the downward force on both objects, and the net force on each object is no longer proportional to the mass of each object. Consequently, the high-mass object accelerates in atmosphere faster than the low-mass object. The high-mass object has a higher terminal velocity; the low-mass object has a lower terminal velocity.
For the purposes of this experiment, buoyancy is functionally irrelevant. The effect of buoyancy is to subtract a fixed mass from each object: A mass equivalent to the mass of air displaced by the object. Effectively, buoyancy slightly reduces the density of both objects. The actual difference in the densities of the two objects is far greater than the slight change due to buoyancy in air, so buoyancy is not a significant factor.
While that is true, two properly selected objects (such as the ones mentioned above) can reduce the effect of air resistance to levels negligible to human perception, demonstrating that heavier objects do not intrinsically fall faster.
Not at all. Our air is made up of physical objects (molecules of oxygen and nitrogen, mostly). Things with more mass, more quickly knock those out of the way.
For a demonstration you can see and more easily wrap your head around, take something just barely heavier than water, and a similarly sized heavy rock and drop them in a pool. You’ll see how much quicker the rock gets to the bottom, because it displaces the water so much faster. Our atmosphere is the exact same.
It seems maybe you’re actually misunderstanding. As I mentioned above, both you and the other commenter are certainly correct that the surrounding atmosphere (water in your case) exerts force on the objects as they fall, with varying effects depending on object density. However, if you take two objects that have vastly more density than the water (let’s say a big tungsten rod and another tungsten rod that has a hollow core), they will drop at approximately the same rate in the water even if their density vs each other varies. The greater the difference of their density versus the density of the medium, the less the effect of the medium. Is there still technically an effect? Sure, but that effect is negligible from a human perceptual perspective.
I understand what you’re saying (call it like a 10" 100 pound tungsten ball vs a 5" 50 pound tungsten ball) but your reasoning and logic of being essentially the same are just silly and the math that would dictate when each would land in atmosphere would still line up perfectly (which would be that the heaviest one will hit first). even if it were a 10,000 pound ball and a 5,000 pound ball.
The difference is the different buoyancy of the balls in air. That’s negligible.