Physics question - gravity

[Usarka]

There's a physics question on the daily stuff quiz today

If you dropped three spheres weighing 1kg, 2kg and 3kg, at the same time from the same height, which would hit the ground first?

The obvious (and deemed correct by stuff) answer is "all at the same time".

But I was thinking... :sherlock: But don't all objects with mass create gravity?

In which case the larger mass object will create an infintessimally greater amount of gravity than the others, therefore the 3kg object will hit the ground first by a fraction of a fraction of a nanosecond.

Have we been lied to as children????? Bastards.

[MSTRS]

You also need to factor in the extra drag created by the heavier object being physically larger. Maybe.
What happens when objects of the same size, but differing mass, are dropped?

[davereid]

There's a physics question on the daily stuff quiz today

If you dropped three spheres weighing 1kg, 2kg and 3kg, at the same time from the same height, which would hit the ground first?

The obvious (and deemed correct by stuff) answer is "all at the same time".

But I was thinking... :sherlock: But don't all objects with mass create gravity?

In which case the larger mass object will create an infintessimally greater amount of gravity than the others, therefore the 3kg object will hit the ground first by a fraction of a fraction of a nanosecond.

Have we been lied to as children????? Bastards.

Acceleration due to gravity actually depends more on what the weight is accelerating towards than the mass of the weight itself.

For example, heavy weights accelerating towards MY foot actually accelerate faster than heavy weights accelerating towards YOUR foot.

This also applies to vehicles.

Acceleration due to value is the rule here.

The expensive motorcycle will accelerate exponentially faster, and more often towards the ground than the inexpensive motorcycle.

[onearmedbandit]

I was always under the assumption that all objects are affected by gravity equally, just on earth due to our atmosphere we don't see that in experiments. Unless of course you conduct the experiment in a vacuum. Myth Busters did an episode on Space the other day, they used one of NASA's vacuum chambers, and they dropped a feather and a hammer at the same time, and of course they both touched the deck at the same time.

[doc]

So fat skydivers fall faster ? Isn't it something to do with reaching terminal velocity ?

[SMOKEU]

So fat skydivers fall faster ? Isn't it something to do with reaching terminal velocity ?

If we're talking about such large distances, then a fat skydiver will have a lot more surface area, and therefore air resistance, in comparison to a skydiver whom is not of such a large carriage.

[gazmascelle]

does the same apply to number twos? What if its solid or liquid?

[avgas]

If your bigger mass is, I dunno.....the size of the moon
yes.

3kg's has fuck all gravity, so in terms of timing how fast it falls - dunno if your will be able to measure it.

I think the russians tested this with Mir, and their space station had like 1 millionth of a G or something.

[avgas]

So fat skydivers fall faster ? Isn't it something to do with reaching terminal velocity ?
Nah - its just looks like that when you see the mess on the ground.
They just fall with more momentum.

[bogan]

heavier objects have a higher force generated by gravity, F1=ma. However wind drag is proportional to size and shape and velocity squared, so (simplified) F2=v^2*size*shape, when the Forces are equal you have terminal velocity. When not you get an acceleration of a=(F1-F2)/m. So if the spheres are same size the heavier one will hit ground first.

[aprilia_RS250]

Tie the three balls up together and drop them together.

What would happen? Would the time taken to drop be faster as it's now heavier than the time it took the 1kg ball to drop?

[Juzz976]

The 3kg would have 3 x the Gravitational force accelerating it towards the earth, but because its 3 x the mass the force needs to be 3 x to get the same acceleration. The 3kg will impact with more energy however.

Generally you neglect aerodynamics friction blah blah unless the duration of acceleration causes the object to approaches terminal velocity or moving through a viscous substance. Then there is more maths but not too hard just invloves drag co effcient, displacement and dens
ity of medium in which object is travelling through.

A mercury ball entering our atmosphere would be a good 1. initial speed, rate of increase in grav acceleration (getting closer to earth), temperature rise causing expansion creating more drag...
Shit getting excited now...memories of school in all...

[Juzz976]

oh yeh increase in air density as approaches earth.

I must be bored, real bored.

[pzkpfw]

What we should do is spend a ton of money sending someone to the Moon, where they can drop a feather and a hammer at the same time, to see which hits the Moon first.

[Juzz976]

What we should do is spend a ton of money sending someone to the Moon, where they can drop a feather and a hammer at the same time, to see which hits the Moon first.

The hammer, the hammer and feather would pull into eachother due to the gravitational force between them. The feather would move toward the hammer faster as the same force applied to a smaller mass. The feather is now taking a longer route towards the moon as its vector has shifted more than the hammer.

Maybe the feather, if the moon is far enough away the feather will collide with the head of the hammer thus causing the hammer and feather to spin (very slowly) the feather will have an affinity towards the centralised mass (hammer head) and the hammer may possibly land ontop of the feather.

[avgas]

The 3kg would have 3 x the Gravitational force accelerating it towards the earth, but because its 3 x the mass the force needs to be 3 x to get the same acceleration. The 3kg will impact with more energy however.
You were so close - all you needed to do was join all the dots and you had a complete the picture.
Why does it have 3 times the G force? Because it needs to move 3 times the mass.....which impacts with 3 times the energy......why.....because it had 3 times the potential energy, created by mass being 3 times the size, and therefore causing the g-force to be larger........

[avgas]

The hammer, the hammer and feather would pull into eachother due to the gravitational force between them. The feather would move toward the hammer faster as the same force applied to a smaller mass. The feather is now taking a longer route towards the moon as its vector has shifted more than the hammer.

Maybe the feather, if the moon is far enough away the feather will collide with the head of the hammer thus causing the hammer and feather to spin (very slowly) the feather will have an affinity towards the centralized mass (hammer head) and the hammer may possibly land ontop of the feather.

WTF!
Your kidding right.
What about the super large rock your standing on, y'know the one that the moon is attracted too?
Or the big glowy thing in the sky - that the solar system is attracted too.

[Juzz976]

WTF!
Your kidding right.
What about the super large rock your standing on, y'know the one that the moon is attracted too?
Or the big glowy thing in the sky - that the solar system is attracted too.

relative distances, acceleration from the objects is of less magnetude and very very much the same vector acceleration is applied to both objects.

Of course the moon is moving so does the hammer and feather fall from zero velocity relative the centre of the universe or at relative moon speed, and in relation to what?

"Honest officer the sun pulled my car into the path of the motorcycle"
------------------------------------------------

"You were so close - all you needed to do was join all the dots and you had a complete the picture."

what came first Chicken or the egg?
-----------------------------------

"The expensive motorcycle will accelerate exponentially faster, and more often towards the ground than the inexpensive motorcycle. "

so if the exponent was ² as with most simple maths your saying a my $10,000 dirt bike accelerates four times quicker than my $5,000 road bike?

[DEATH_INC.]

Acceleration due to value is the rule here.

The expensive motorcycle will accelerate exponentially faster, and more often towards the ground than the inexpensive motorcycle.
Soooo, if we take a MV and a Hyobung and throw them both off the skytower the MV will hit the S-class in the carpark first?

[saxet]

What we should do is spend a ton of money sending someone to the Moon, where they can drop a feather and a hammer at the same time, to see which hits the Moon first.

They've already done it and they landed at the same time.
I might be wrong here but I believe that experiment was definitive proof of Newtons theories.

[Juzz976]

Soooo, if we take a MV and a Hyobung and throw them both off the skytower the MV will hit the S-class in the carpark first?

I theory yes, but this is mostly attributed to the repulsion forces the hyobung has with the general population of the planet its is falling toward.

[Winston001]

Hammer and feather....


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[NighthawkNZ]

Gravity is a myth the earth sux

[Brian d marge]

Gravity only works on the over 40s

Stephen

[schrodingers cat]

Meanwhile, back in reality land...


All those brains and no fucking clue!

[davereid]

Soooo, if we take a MV and a Hyobung and throw them both off the skytower the MV will hit the S-class in the carpark first?


Absolutely.

In fact, even if the S-Class was not actually directly under the MV, it would find an angle of descent to ensure it hit the S-Class anyway.

This effect is known as mutual entrophy, and it is the the reason that a-likes attract.

So the expensive motorcycle is attracted by mutual entrophy to the expensive car. Even when not crashing, they will be found in the same neighbourhoods, or even as close as the same garage.

It also explains why all the asians live in Howick and thus can be considered one of the more robustly proven principles of physics.

[Usarka]

Soooo, if we take a MV and a Hyobung and throw them both off the skytower the MV will hit the S-class in the carpark first?

No it'll hit the Bongo van because of the gravity created by the extra mass of all the kids in the back eating KFC until the olds come back from the pokies.

[Swoop]

If we're talking about such large distances, then a fat skydiver will have a lot more surface area, and therefore air resistance, in comparison to a skydiver whom is not of such a large carriage.
Nope. Fatties plummet faster.

[Hitcher]

If we're talking about such large distances, then a fat skydiver will have a lot more surface area, and therefore air resistance, in comparison to a skydiver whom is not of such a large carriage.

Not true. All mammals have the same surface-area-to-volume ratio, irrespective of whether or not they are gerbils or whales. Or obese skydivers.

[marie_speeds]

correct answer? hmmmm

mad

[Winston001]

Not true. All mammals have the same surface-area-to-volume ratio, irrespective of whether or not they are gerbils or whales. Or obese skydivers.

AHA!
The Allometric Scaling of Organisms





Suck on that my lad....:yes: