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Why do heavier things fall faster than lighter things if dropped from a certain height...

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himanshu9 | eNotes Newbie

Posted January 2, 2010 at 6:52 PM via web

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Why do heavier things fall faster than lighter things if dropped from a certain height ?

related to gravitational force.

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mkcapen1 | Middle School Teacher | (Level 3) Valedictorian

Posted January 2, 2010 at 7:06 PM (Answer #3)

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Not at all. Two objects falling from the same place despite their weight differences will hit the ground at the same time.  You can test this theory by taking a tennis ball and a golf ball and standing on a table.  Hold your arms out at the same height and drop the objects.  If your arms are held at the same height the balls will hit the ground at the same time.  The times when this would not occur is if one object is flat paper and the other object is a ball.  The paper will have more resistance because of its shape.

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boyboy-2144 | eNotes Newbie

Posted October 26, 2013 at 3:33 AM (Answer #28)

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They have more mass:)
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caledon | High School Teacher | (Level 3) Educator

Posted July 11, 2014 at 4:34 AM (Answer #33)

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Most of the time, people ask this question with the idea of a Newtonian "feather vs. bowling ball" concept in mind. Based on those terms, the typical answer is correct: two objects will fall at the same speed in a vacuum, and air resistance can appear to make an object fall slower. However, there is a surprising, but more complicated nuance to this problem.

Every action has an equal and opposite reaction. This means that, just as the Earth is exerting a gravitational force on the objects, the objects are exerting a gravitational force on the Earth. Just as much as the objects fall onto the Earth, the Earth falls onto the objects as well. It's just the fact that the Earth is so much larger and more massive that we default to viewing things from the first perspective and not the latter. Nevertheless, the gravitational force exerted on the Earth by the objects cannot be ignored.

Gravitational force is determined by the Universal Gravitation law:

`F = (GmM)/r^2`

where m and M are the two masses involved in the interaction. If we do two separate calculations, one for the mass of the lesser object, and one for the mass of the greater object, we can see that there will actually be a larger gravitational force involved with the more massive object.

This is where most people would interject that, well, yes, the larger mass needs a larger force in order to achieve the same acceleration. But reverse the frame of reference; now let's consider this from the point of view of the objects doing the pulling, instead of the Earth. Now we can see that the force exerted by the larger mass is doing more pulling than the smaller mass. The Earth will "hit" the larger mass first.

Mind you, the scale that this takes place on is smaller than we can actually measure with our current technology. However, it makes sense if you consider it in a different way; If you held a brick and the Moon at the same height and dropped them, which would hit first?

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pohnpei397 | College Teacher | (Level 3) Distinguished Educator

Posted January 2, 2010 at 6:58 PM (Answer #2)

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This is not an accurate statement.  Heavier objects do not fall faster than lighter objects when they are dropped from a certain height IF there is no resistance from the air.  So, if you were in a vacuum, the two things would fall at the same rate.

The only thing that makes a heavier thing fall faster than a lighter thing in real life is the fact that heavier objects usually have more mass per surface area than do lighter things.  Because of this, the resistance from the air slows the fall of the lighter thing.

But if both objects had the same ratio of mass to surface area, they would fall at the same rate.

So, the only thing that makes a lighter thing fall more slowly is the resistance from the air.

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krishna-agrawala | College Teacher | (Level 3) Valedictorian

Posted January 2, 2010 at 7:43 PM (Answer #4)

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The speed at which things fall when dropped from certain height is the determined by the resultant of two forces acting on the body. The first is the gravitational force acting on the body. Opposing this force is the air resistance offered to the movement of the body.

Under the effect of gravitational force alone all bodies will fall with the same acceleration and speed, as the force acting on the body is directly proportional to its mass. However the air resistance offered is dependent on surface area and shape of the body. when two bodies of same mass but different densities are dropped from a given height, the body with lower density, due to its greater size and surface area than the denser body, will experience greater resistance from air and therefor will have lower speed.

Even for objects of same density the ratio if surface area to mass increases as the size is reduced. Therefore objects of smaller size experience greater air resistance per unit mass as compared to that of a bigger size. This the reason why a small particle of dust taken from a stone will fall at much slower speed as compared to the stone.

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readerofbooks | College Teacher | (Level 2) Educator Emeritus

Posted January 2, 2010 at 7:50 PM (Answer #5)

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There are two ways to answer this question. The first way is to challenge the accuracy of the question, since gravity is constant for all objects. In a windless environment, basically a vacuum, a piece of paper will fall at the same speed as a metal arrow. That sounds like a lie, but it is completely true. The second way to answer the question is by taking into consideration wind resistance. Those items that are streamlined more will fall faster, because these things are able to cut the wind. Those items that are more blunt and cannot cut the wind will move slower.

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neela | High School Teacher | (Level 3) Valedictorian

Posted January 2, 2010 at 8:34 PM (Answer #6)

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Rather than 'lighter 'or 'heavier' , I use 'less dense' or 'more  dense' objects and  I also pressume a medium of air through which the objects fall.

The falling free in vaccum and falling through air are 2 slightly different concepts. Air acts as a buyant liquid on the falling objects. In liquid all objects of leser density than the liquid floats. There is the principle of Archemedes supporting this. Similarly any thing which is less dense than air does not fall but float in air. This is because air makes  a  buoyant force which thrusts up  the obect with less density than that of  air.

Secondly all things in air looses a weight which is equal to the volume of the air dispelled by the object by the principle of Archimedes. Therefore, the lighter density objects having larger volume loose more weight by the buoyant force of air (we call this the air resistance under the context) compared to the equivalent mass of denser objects. That is the reason why we see the lighter objects fall slower. This could be seen and confirmed (i)from the example of solid iron  and a flywood of identical mass falling from around 100 metr height and (ii) or solid iron and a solid flywood of identical volume and shape falling from 100 meter.

Conclusion: The less dense objects fall slower than more dense objects in the medium of air. But in vaccum they should fall with equal velocity, irrespective of their shape, mass or density obeying the Law of gravitation.

 

 

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friendjoy | Student, Grade 10 | (Level 1) Salutatorian

Posted November 7, 2011 at 10:31 PM (Answer #7)

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it is related to gravitational force which acts upon the bodies of earth...

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thevinn | Student, Grade 9 | eNotes Newbie

Posted November 14, 2011 at 12:11 AM (Answer #8)

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The only difference is wheather they are subject to air, and if so, are they the same size?If there is air I is possible to get lighter object to fall faster, if there is no air. Then they will fall at the same speed. (If released at the same time.)

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javaria95 | Student, Grade 10 | (Level 1) Honors

Posted November 14, 2011 at 6:59 AM (Answer #9)

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This is not an accurate statement. Heavier objects do not fall faster than lighter objects when they are dropped from a certain height IF there is no resistance from the air. So, if you were in a vacuum, the two things would fall at the same rate. The only thing that makes a heavier thing fall faster than a lighter thing in real life is the fact that heavier objects usually have more mass per surface area than do lighter things. Because of this, the resistance from the air slows the fall of the lighter thing. But if both objects had the same ratio of mass to surface area, they would fall at the same rate. So, the only thing that makes a lighter thing fall more slowly is the resistance from the air.

 

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deepakkumarkaran | Student, Undergraduate | (Level 2) eNoter

Posted November 17, 2011 at 7:02 PM (Answer #11)

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Rather than 'lighter 'or 'heavier' , I use 'less dense' or 'more  dense' objects and  I also pressume a medium of air through which the objects fall.

The falling free in vaccum and falling through air are 2 slightly different concepts. Air acts as a buyant liquid on the falling objects. In liquid all objects of leser density than the liquid floats. There is the principle of Archemedes supporting this. Similarly any thing which is less dense than air does not fall but float in air. This is because air makes  a  buoyant force which thrusts up  the obect with less density than that of  air.

Secondly all things in air looses a weight which is equal to the volume of the air dispelled by the object by the principle of Archimedes. Therefore, the lighter density objects having larger volume loose more weight by the buoyant force of air (we call this the air resistance under the context) compared to the equivalent mass of denser objects. That is the reason why we see the lighter objects fall slower. This could be seen and confirmed (i)from the example of solid iron  and a flywood of identical mass falling from around 100 metr height and (ii) or solid iron and a solid flywood of identical volume and shape falling from 100 meter.

Conclusion: The less dense objects fall slower than more dense objects in the medium of air. But in vaccum they should fall with equal velocity, irrespective of their shape, mass or density obeying the Law of gravitation.

 

 

Really accurate. can you add me as your friend?

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joy1495 | Student, Grade 10 | (Level 1) eNoter

Posted November 24, 2011 at 12:42 AM (Answer #12)

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This question is related to weight. Weight is defined as the amount of force by which earth pulls an object towards it. We know; W=mg where, m=mass and g=9.8 metre per second squre. So if a heavier and a lighter object is thrown simultaneously from same height the heavier object falls quickly because it has more mass than the lighter object and the g is always constant.

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jess112 | Student | eNotes Newbie

Posted November 29, 2011 at 1:18 AM (Answer #13)

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heavier objects do fall faster than lighter objects do as the heavy wait pulls the object down to the ground by gravity and the lighter object gently floats to the ground very slowly.

this comment is not completely accurate but thats my point of veiw and my opinion

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aabbeir | Student, Grade 10 | (Level 1) Honors

Posted December 7, 2011 at 3:09 AM (Answer #15)

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weight is the key. In vacuums and space they fall at the same time because they are in free fall.

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rockonhunter | Student | (Level 1) Honors

Posted December 15, 2011 at 7:21 AM (Answer #16)

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the heavyer the mass is the faster it will drop

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ngyunhui | Student | (Level 1) Honors

Posted December 16, 2011 at 3:35 PM (Answer #17)

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In a vacuum, heavy things fall at the same rate as light things. This fact of Newtonian physics has been proved many times over. During the Appollo 15 mission a feather and a hammer were dropped and this was demostrated very graphically.

However, in an atmosphere heavier things generally fall faster than lighter things although the opposite can also be true. This isn't because gravity works any differently, but because of "drag" - air friction acting to slow the falling object. A feather has much more surface area compared to its weight than a hammer does, and so in an atmosphere it falls slower. Conversely, a bowling ball is much lighter than an airplane, but due to aerodynamic factors the ball would fall much faster

 

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shivangi128 | Student, Undergraduate | eNotes Newbie

Posted December 21, 2011 at 6:53 PM (Answer #18)

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All objects fall at same rate. There if you will fall an elephant and mice, they both will reach at same time

only difference can be due to the surface area of the object, more surface area encounters more air resistance resulting in less speed.

but IN VACCUM when objects with different surface ares fall, they fall at same speed

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adhithya | Student, Grade 11 | eNotes Newbie

Posted December 27, 2011 at 10:10 AM (Answer #19)

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heavier objects fall faster than lighter objects only in the presence of air. Newton illustrated this in his "Feather and Coin" experiment.

 

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manish001 | Student, Undergraduate | (Level 2) eNoter

Posted December 28, 2011 at 10:02 PM (Answer #20)

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No,heavy things dont fall faster than the lighter ones.Its just an illusion.but in earth's surface,due to air resistance the object having greater surface area faces greater air resistence but in vaccum both lighter as well as heavier objects fall simultaneously.Due to air resistence,objects like feather falls slowly as it is highly affected by the resistence provided by air.

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valie77 | Student, Undergraduate | (Level 1) Honors

Posted December 31, 2011 at 1:14 AM (Answer #21)

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because of gravity...

but did you know that if you threw a one pence coin of the iffle tower in france it could kill a person at the bottem by hitting them on the head !!!!!!!!!

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vasudanainakumari | Student, Undergraduate | (Level 1) Honors

Posted January 8, 2012 at 10:02 PM (Answer #22)

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as hevier objects posses more mass when compared to lighter objets... each and every parctile of the object experience gravitational force

where as in case of light objects  it has less mass....

and aslo lighter and heavier both experience air pressure on them but hevier objects can withstand against the air pressure as its mass is high..

where as lighter ones cant withstand the presure so they move along with air....

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aznboy578 | Student, Grade 9 | (Level 1) Valedictorian

Posted January 26, 2012 at 7:37 AM (Answer #23)

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I agree with #1 heavier objects do not fall faster than lighter objects. This will only happen if you do this. Paper and a rock which one falls faster the rock. Only because the surface area.

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asmathwiz | Student | (Level 1) Honors

Posted February 11, 2012 at 10:14 PM (Answer #24)

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I agree with #3.Both fall at the same time.

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bishalnaskar | Student, Undergraduate | (Level 1) Salutatorian

Posted February 25, 2012 at 10:46 AM (Answer #25)

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Due to the effect of gravitational force all bodies fall with the same acceleration and speed in vaccum but in some other propagating media as the force acting on the body is directly proportional to its mass and also air friction comes into play.

As a result of which the body acquiring higher momentum<as a result of higher mass as p=mv> falls quicker than the lighter body...also surface area and densities are factors on which this depends..........

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x-sumit-x | Student, Grade 10 | (Level 1) Honors

Posted February 28, 2012 at 6:42 AM (Answer #26)

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it is beacause the heavier objects can attarct to the gravity faster

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nb-zhu | Student, Grade 11 | eNotes Newbie

Posted May 9, 2013 at 2:23 PM (Answer #27)

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Objects that are heavier will fall faster than objects that are lighter

I did an experiment by manipulating the falling object's mass, and the results confirm this statement.

Heavier objects have a greater terminal velocity because they accelerate faster, and have a greater downwards force, meaning that the object requires a greater air resistance to reach that terminal velocity. When the object reaches terminal velocity, there is zero acceleration, so when the objects mass is increased, the terminal velocity is also increased. This means it takes longer for that object to reach its terminal velocity, and during that time it is constantly accelerating. So yes objects that are heavier do fall faster!

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aeherb3 | (Level 1) eNoter

Posted January 7, 2014 at 8:42 PM (Answer #29)

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This can be answered best by using the equation Force= mass x acceleration. 

Please note, that there are two environments in which there will be different answers.  In a vacuum, that is, in the absence of friction, both objects will fall at the same time. Surface area and mass become important however as we imagine this scenario on our earth.  On earth where every object experiences gravity, the two objects will fall at different rates. 

Let's imagine an elephant and a feather, both dropped from the top of a very tall building.  When you drop the objects, they are experiencing the same acceleration due to gravity, but due to their different masses, they are both exerting different amounts of "downward" force.

Elephant= 1000 kg

Feather= 1kg

Acceleration due to gravity= 9.8m/s/s``

Downward force being exerted by elephant:  F= (1000kg) x (9.8m/s/s) = 9800N

Downward force being exerted by feather: F=(1kg) x (9.8m/s/s) = 98N

The next thing you have to consider is terminal velocity- Terminal velocity is when acceleration stops (this is when the force of gravity and the force of air resistance are balanced).  The feather requires much less air resistance for it to reach terminal velocity.  The elephant requires a  great amount of air resistance to slow and come to a terminal velocity. 

You can experiment with this phenomenon by designing a parachute device- try to make one that reaches terminal velocity quickly so as to protect it's "passenger" (try to save a raw egg from cracking).  You can make your parachute with cheap household materials and experiment with different masses of your parachute device, different sizes of parachute, and different design characteristics.  Keep in mind the principals of Newton's Laws throughout your experimenting.

Happy engineering!

Sources:

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atyourservice | Student, Grade 10 | (Level 3) Valedictorian

Posted March 22, 2014 at 11:40 PM (Answer #30)

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they drop at the exact same rate, it is just that earth has an air resistance which cause lighter things to float a little bit

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zumba96 | TA , Grade 11 | (Level 2) Valedictorian

Posted April 30, 2014 at 3:05 AM (Answer #31)

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Based on the mass if you dropped a feather from a 500 foot height and a bowling ball from the same height of course the bowling ball would hit the ground first because the mass would create more acceleration

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crystaltu001 | Student, Grade 10 | (Level 1) Valedictorian

Posted July 6, 2014 at 7:27 AM (Answer #32)

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It's based on the mass of the object. If 2 different things that each weighed differently were dropped the heavier item would hit the ground first since it has more mass and the lighter things tend to float for a little bit before it actually hits the ground

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givingiswinning | Student, Grade 10 | (Level 1) Valedictorian

Posted July 31, 2014 at 11:23 AM (Answer #34)

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 the heavier item would hit the ground first

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ibrahimrehan | TA , Grade 9 | (Level 2) Honors

Posted December 7, 2014 at 5:22 PM (Answer #35)

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Heavier things have a higher mass than lighter objects , due to this , heavier mass objects have a greater momentum , which is calculated as mass x velocity

Hence the greater the mass , the greater the momentum of the object and so the object with a higher mass / weight will fall faster than lighter objects .

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deepakkumarkaran | Student, Undergraduate | (Level 2) eNoter

Posted November 17, 2011 at 6:54 PM (Answer #10)

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This is not an accurate statement.  Heavier objects do not fall faster than lighter objects when they are dropped from a certain height IF there is no resistance from the air.  So, if you were in a vacuum, the two things would fall at the same rate.

The only thing that makes a heavier thing fall faster than a lighter thing in real life is the fact that heavier objects usually have more mass per surface area than do lighter things.  Because of this, the resistance from the air slows the fall of the lighter thing.

But if both objects had the same ratio of mass to surface area, they would fall at the same rate.

So, the only thing that makes a lighter thing fall more slowly is the resistance from the air.

Can this be as per Archimedis principle and concept of buoyancy?

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smeghead | College Teacher | eNotes Newbie

Posted November 29, 2011 at 11:35 PM (Answer #14)

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Why do we always talk about "falling"!  This description only lends itself to confusion.  The "falling" experiment was only a means to prove something which is already easy to explain in its base terms.

Gravity is a force of attraction between any instances of mass in the universe, which when acting on any other mass, will pull toward the other.  Large things like planets seem to be doing all the pulling in space, but gravity is a constant and its force is just a product of the parts involved.  All things have this gravitational constant at an atomic level.

The only resistance of real importance here is that of a mass's desire to stay in place.  An object at rest will tend to stay at rest, more-so given its mass related to the force acting on it.  Larger masses have greater susceptibility to the effects of gravitational force than smaller masses, but also greater resistance to its acceleration effects!  "Heavy" things are actually LESS likely to "fall"!!!  They do so, begrudgingly!

This has nothing to do with air resistance or weather balloons.  Its just Newton's basic natural principle.  The force is the "product" (m1 x m2) of the masses, but the resistance to change is the factor that makes "heavy" objects acted on by a single body actually accelerate toward the gravitational center of that body at the same rate as its "lighter" counterpart, which may have less "mass", but also therefore less "resistance" to said gravity. Equal!

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ahmedrehan | (Level 1) Honors

Posted December 17, 2014 at 6:48 PM (Answer #36)

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Because of their higher mass and greater momentum as a result .

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