• Log in | Sign up@lemmy.world
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    2 hours ago

    To be fair to Archimedes, heavy objects do usually fall faster than light ones*, and to be fair to Newton, stuff coming towards you usually has a higher relative velocity than things going away from you.+

    *You need your objects to be weigh a lot relative to their air resistance to notice otherwise.

    +You need some pretty ambitious equipment to detect that electromagnetic radiation such as light does not follow this pattern.

  • WizardofFrobozz@lemmy.ca
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    5 hours ago

    I am most certainly not a science whiz but it’s so goddamn funny to see this whole comment section full of people just… explaning and correcting each other poorly with varying degrees of correctness. Just like 50 half-true and misremembered tidbits from everyone’s intro to high school physics class, blindly seeking targets in space. I promise you guys, there’s a very straight answer to this like two or three clicks away, written more clearly and succinctly than anyone here is managing to do.

  • DreadPirateShawn@lemmy.blahaj.zone
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    5 hours ago

    Rosencrantz: [holds up a feather and a wooden ball] Look at this. You would think this would fall faster than this.
    [drops them. ball hits the ground first]
    …and you would be absolutely right.

    ~ Rosencrantz & Guildenstern Are Dead

    • LustyArgonian@lemmy.world
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      6 hours ago

      https://www.usgs.gov/water-science-school/science/how-much-does-a-cloud-weigh

      Doing the math: 1,000,000,000 x 0.5 = 500,000,000 grams of water droplets in our cloud. That is about 500,000 kilograms or 1.1 million pounds (about 551 tons). But, that “heavy” cloud is floating over your head because the air below it is even heavier— the lesser density of the cloud allows it to float on the dryer and more-dense air.

      Planes, helicopters- lots heavy stuff not falling faster than lighter ones

  • it_depends_man@lemmy.world
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    12 hours ago

    The thing that always gets me about the Renaissance is Galileo:

    He did those experiments with things falling down? Measuring speed?

    Yeah. Without a clock.

    The theory for how to build those came later, based on what Galileo did.

    • MajorMajormajormajor@lemmy.ca
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      9 hours ago

      Man, being a cop must have sucked before they invented time.

      Officer: do you know how fast you were going?

      Lord: No, do you?

      Officer grumbles: you’re free to go.

      Carriage pulls away

      Officer ClocknTime: For now, for now.

  • missingno@fedia.io
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    13 hours ago

    When accounting for air resistance, heavy objects do fall faster than light ones. They couldn’t test in a vacuum back then, they only knew how things work here in Earth’s atmosphere.

    • Frezik@lemmy.blahaj.zone
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      12 hours ago

      A similar size chunk of iron and coal would have done the experiment just fine. Any two objects of the same shape and size but significantly different densities.

      • missingno@fedia.io
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        12 hours ago

        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.

        • psud@aussie.zone
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          10 hours ago

          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

          • missingno@fedia.io
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            10 hours ago

            minus drag

            On Earth, this is the part that makes it so that objects do not fall at the same speed.

            on the moon

            This is the type of experiment they could not do 2000 years ago.

            • psud@aussie.zone
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              7 hours ago

              minus drag

              On Earth, this is the part that makes it so that objects do not fall at the same speed.

              That is incorrect. Drag affects both equally. The difference is caused by buoyancy, less dense objects feel more buoyancy

              • Rivalarrival@lemmy.today
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                6 hours ago

                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.

          • mnemonicmonkeys@sh.itjust.works
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            10 hours ago

            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

          • Rivalarrival@lemmy.today
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            10 hours ago

            Read their claim again: they are specifically describing the effect of air resistance. Their claim is perfectly consistent with the lunar feather/hammer experiment.

            • psud@aussie.zone
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              7 hours ago

              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

              • Rivalarrival@lemmy.today
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                6 hours ago

                They did. You didn’t understand what they said.

                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.

        • StellarExtract@lemmy.zip
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          11 hours ago

          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.

          • ColeSloth@discuss.tchncs.de
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            10 hours ago

            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.

          • psud@aussie.zone
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            10 hours ago

            The difference is the different buoyancy of the balls in air. That’s negligible.

    • waigl@lemmy.world
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      12 hours ago

      Nope, denser objects fall faster than less dense ones (through the air). Remember: A kilogram of feathers is just as heavy as a kilogram of lead.

      • PastafARRian@lemmy.dbzer0.com
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        4 hours ago

        Not really true, it’s definitely possible for a less dense object to fall faster than a denser one. A drop of water will fall faster than a parachute made of nylon, which will fast much faster than a glider plane made of metal.

      • mnemonicmonkeys@sh.itjust.works
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        10 hours ago

        Nope, denser objects fall faster than less dense ones (through the air).

        Technically it’s objects with a higher mass-to-drag ratio, but most of the time it’s close enough

  • Zerush@lemmy.ml
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    11 hours ago

    With same gravity constance everything fall down at the same speed, but only in a vacuum. In an atmosphere there count the air resistance of an object, even if they are made of the same material and weight, an iron sphere of 1 kg fall faster than a iron sheet of 1 kg.

      • falcunculus@jlai.lu
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        7 hours ago

        I assume you mean keeping the outer diameter the same and making one ball lighter than the other. That’s clever, it would eliminate aerodynamism as a factor.

        However wouldn’t results still vary, since hollowing out the metal ball increases its buoyancy ? (Archimedes’ principle).

        • heatofignition@lemmy.world
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          5 hours ago

          They would have the same coefficient of drag, correct, but the air resistance would end up having more effect on the lighter mass of the hollow sphere, so it would be slightly slower to fall.

          Archimedes principle here is accounted for in the different weights. Everything that you can put on a scale is already being acted on by Archimedes principle in air.

    • ryannathans@aussie.zone
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      7 hours ago

      Except if you could measure exactly the speed of objects falling in a vacuum, the heavier object would appear to fall faster due to the gravitational pull on the earth

        • heatofignition@lemmy.world
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          5 hours ago

          R^2 is on the bottom. We don’t ignore the mass of one object because it’s insignificant, that would make the top of that equation 0 and the object wouldn’t fall at all.

          That nifty gravitational law gives you the force of gravity on an object, not the acceleration. Force also equals mass times the resultant acceleration, right? So Fg1 = m1*A1 = G*M*m1/r^2 and Fg2 = m2*A2 = G*M*m2/r^2. m1 and m2 are present on both sides of those equations, respectively, so they cancel, and you get A1 = G*M/r^2 and A2 = G*M/r^2, which are identical. The mass of an object affects the force of gravity, but when you look at acceleration the mass terms cancel out.

      • Zerush@lemmy.ml
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        7 hours ago

        No, mass or weight of an object is irrelevant, in one of the jurney to the Moon, astronauts demostrate it with an hammer and a feather on the moon that both fellt at the same speed. It exist one gravity aceleration, on earth is 9,82 ms², which is the force of acceleration which experiment any object on Earth, the only difference which can slow it down is the resistant of air, this can be different in each object, but without atmosphere there is nothing which slow down the acceleration of the object, it’s irrelevant the material, weight, mass or form. Basic physic

        https://www.youtube.com/watch?v=Oo8TaPVsn9Y

  • Carl [he/him]@hexbear.net
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    12 hours ago

    They did figure out the earth was round and measure its size with sticks and shadows though, so that’s pretty cool.

  • Skullgrid@lemmy.world
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    13 hours ago

    I mean, yes and no. ~~https://en.wikipedia.org/wiki/Terminal_velocity#Physics ~~ Heavier objects have a higher “max speed” that they can fall at, compared to lighter objects. The acceleration to that relative speed is constant though. More or less.

    IE : While a bowling ball and a ping pong ball might start falling at the same initial rate, eventually the bowling ball will fall faster.

    EDIT : Ignore me for now, I need to do more digging.