The Naked Scientists

The Naked Scientists Forum

Author Topic: How much does the Earth weigh?  (Read 56716 times)

BenTheH33

  • Guest
How much does the Earth weigh?
« on: 23/11/2010 10:30:04 »
BenTheH33 asked the Naked Scientists:
   
One thing I have wondered is how much does earth weigh? How many pounds does earth way, and if we don't yet know, do you think it would ever be possible to guess accurately?

KEEP UP THE GREAT WORK!!!

Ben

What do you think?
« Last Edit: 23/11/2010 10:30:04 by _system »


 

Offline Pikaia

  • Full Member
  • ***
  • Posts: 81
    • View Profile
 

Offline QuantumClue

  • Hero Member
  • *****
  • Posts: 613
    • View Profile
How much does the Earth weigh?
« Reply #2 on: 23/11/2010 12:22:49 »
The earth weighs 6.5 x 10^27 in tons. But this is nothing on astronomical terms. Even a spoonful of neutron star would weigh about the same as all the buildings on earth.
 

david holthaus

  • Guest
How much does the Earth weigh?
« Reply #3 on: 23/11/2010 13:30:05 »
david holthaus asked the Naked Scientists:
   
how much does the earth weigh?

What do you think?
« Last Edit: 23/11/2010 13:30:05 by _system »
 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
How much does the Earth weigh?
« Reply #4 on: 23/11/2010 14:58:28 »
Calculating the mass of the Earth is fairly straightforward, but weight is relevant only in relation to gravity, but perhaps it was mass you were thinking of, in which case it's something like 5.9737 ◊ 10ą24kg.
 

Offline maffsolo

  • Sr. Member
  • ****
  • Posts: 280
    • View Profile
How much does the Earth weigh?
« Reply #5 on: 23/11/2010 15:06:49 »
I found a site that relates to the mass of the earth...
http://hypertextbook.com/facts/2002/SamanthaDong2.shtml
Bill S has it I found this may be an approximate derived calculation since there is mass collecting here from space, constantly.

Let's see if I have it correct
Below: In this definition of Weight I will say earths weight is zero. If this is a true definition...

Weight is the force that results from the acceleration by gravity on the mass of an object.[1]

Sometimes it is defined in operational terms of the weighing process as the force exerted by an object on its support,[2] which also illustrates the condition of weightlessness.

Standing at rest on a weighing scale on Earth, a person's weight equals its mass multiplied by the gravitational acceleration of Earth. However, in a free falling elevator, a scale indicates a zero weight, as no net force is exerted by the body on the support; the person experiences weightlessness. Similarly, in a space craft in orbit around the Earth the weight is also zero, as the orbit represents a free fall. On the surface of the Moon, an object's weight is approximately one sixth of the weight at rest on Earth, as the gravitational force exerted by the Moon is much smaller than that of Earth.

The weight of an object, often denoted W, is defined as the gravitational force exerted on it. It is the product of the mass m of the object and the local gravitational acceleration g:[3] W = m g. In the International System of Units (SI), the unit of measurement for weight is that of force, the newton.

On the surface of the Earth, the acceleration due to gravity is approximately constant; this means that the magnitude of an object's weight on the surface of the Earth is proportional to its mass. In situations other than that of a constant position on the Earth, so long as the acceleration does not change, the force it exerts against support in any accelerated frame is proportional to its mass, also. In everyday practical use, therefore, including commercial use, the term weight is commonly used to mean mass.

http://en.wikipedia.org/wiki/Weight
« Last Edit: 23/11/2010 15:14:37 by maffsolo »
 

Offline syhprum

  • Neilep Level Member
  • ******
  • Posts: 3823
  • Thanked: 19 times
    • View Profile
How much does the Earth weigh?
« Reply #6 on: 23/11/2010 16:30:34 »
The value quoted by QuantumClue is not correct the correct value is 5.9742 ◊ 10^24 kilograms
« Last Edit: 23/11/2010 16:32:40 by syhprum »
 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
How much does the Earth weigh?
« Reply #7 on: 23/11/2010 16:55:25 »
We are talking about mass rather that weight, yes?

We seem to have two threads dealing with the same question. :P
« Last Edit: 23/11/2010 17:10:43 by Bill S »
 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
How much does the Earth weigh?
« Reply #8 on: 23/11/2010 17:08:55 »
Good answer, maffsolo, but,David, is that what you were looking for?
 

Offline maffsolo

  • Sr. Member
  • ****
  • Posts: 280
    • View Profile
How much does the Earth weigh?
« Reply #9 on: 23/11/2010 17:18:31 »
We are talking about mass rather that weight, yes?

We seem to have two threads dealing with the same question. :P

http://www.thenakedscientists.com/forum/index.php?topic=35366.msg331835#msg331835

There seems to be a controversy on terminology with this question We need to call a doctor in to prescribe a solution
Yelling for MEDIC @#$%^&
 

Offline BenV

  • Neilep Level Member
  • ******
  • Posts: 1503
    • View Profile
How much does the Earth weigh?
« Reply #10 on: 23/11/2010 17:22:13 »
Two identical questions merged - sorry if it's a bit muddled right now!
 

Offline maffsolo

  • Sr. Member
  • ****
  • Posts: 280
    • View Profile
How much does the Earth weigh?
« Reply #11 on: 23/11/2010 17:25:59 »
Two identical questions merged - sorry if it's a bit muddled right now!

Thank you for the first aid
 

Offline QuantumClue

  • Hero Member
  • *****
  • Posts: 613
    • View Profile
How much does the Earth weigh?
« Reply #12 on: 23/11/2010 17:35:34 »
The value quoted by QuantumClue is not correct the correct value is 5.9742 ◊ 10^24 kilograms

Mine was in tons. Not kilograms.
 

Offline imatfaal

  • Neilep Level Member
  • ******
  • Posts: 2787
  • rouge moderator
    • View Profile
How much does the Earth weigh?
« Reply #13 on: 23/11/2010 17:54:55 »
10^27 tonnes DOES NOT equal 10^24 kilogrammes.  Your answer was 10^6 times too big
 

Offline QuantumClue

  • Hero Member
  • *****
  • Posts: 613
    • View Profile
How much does the Earth weigh?
« Reply #14 on: 23/11/2010 18:08:49 »
Oh I see. Well that's not good.
 

Offline maffsolo

  • Sr. Member
  • ****
  • Posts: 280
    • View Profile
How much does the Earth weigh?
« Reply #15 on: 23/11/2010 19:04:22 »
Plug and chug convergence calculator

http://www.onlineconversion.com/weight_all.htm




5.9736e+24 kilogram = 9.4068097813e+23 stone

And I thought Earthy was the third stone from the Sun
« Last Edit: 23/11/2010 19:09:13 by maffsolo »
 

Offline QuantumClue

  • Hero Member
  • *****
  • Posts: 613
    • View Profile
How much does the Earth weigh?
« Reply #16 on: 23/11/2010 19:37:41 »
Plug and chug convergence calculator

http://www.onlineconversion.com/weight_all.htm




5.9736e+24 kilogram = 9.4068097813e+23 stone

And I thought Earthy was the third stone from the Sun

I apologize, we all make mistakes. That calculator will definately come in useful in the future.
 

Offline maffsolo

  • Sr. Member
  • ****
  • Posts: 280
    • View Profile
How much does the Earth weigh?
« Reply #17 on: 23/11/2010 19:51:18 »
Plug and chug convergence calculator

http://www.onlineconversion.com/weight_all.htm




5.9736e+24 kilogram = 9.4068097813e+23 stone

And I thought Earthy was the third stone from the Sun

I apologize, we all make mistakes. That calculator will definately come in useful in the future.

No need to appologize I am the master of mistakes.
I can do best with my eyes closed.

I sat here and tried to convert it and I found I was slipping, to double check myself I went to see if my conversion was correct. I was having a bit of a problem with a simple setup and combinding the exponents for a result.

I am here just to keep my gray matter in one mass, I can be trained...:)
 

Offline Foolosophy

  • Sr. Member
  • ****
  • Posts: 218
    • View Profile
How much does the Earth weigh?
« Reply #18 on: 30/11/2010 13:07:57 »
The weight of the earth is equal to zero because it is in free fall motion around the sun

The earth's MASS however can be determined in a variety of ways

cheers
 

Offline thedoc

  • Forum Admin
  • Administrator
  • Sr. Member
  • *****
  • Posts: 511
  • Thanked: 12 times
    • View Profile
How much does the Earth weigh?
« Reply #19 on: 10/12/2010 15:26:06 »
We discussed this question on our  show
  Chris -  The stated weight Ė mass, we should more accurately, of the Earth is about 6 x 1024 kilograms. In other words, if you turn that into tons, itís 6 with 21 zeros after it, tons. So pretty heavy, but the big question is and this is where Dave can help me out, how do we actually know that something on the scale of the Earth that we can't physically put on a pair of scales, how do we know how much that weighs because Archimedes famously said, ďIf you give me a lever long enough and somewhere far enough away to stand, I could lift up the EarthĒ but how would we have calculated how much the earth actually weighs, Dave?
Dave -  Well, the simple way of doing this is because anything with a mass affects everything around it due to gravity. If itís something roughly spherically symmetrical, you can assume that all the mass is in the centre of the planet and it behaves as if it was all the mass is right in the centre, due to some neat bits of maths. Basically, what you have to do is - if you know how much gravitational force a kilogram of anything will apply to another kilogram of anything, and you know how much force a kilogram of substance is being attracted to the Earth and you know how big the Earth is, you can work out how much mass must be in the Earth. The second part of that is really easy. Working out how much force a kilogram produces is really difficult because itís about 10-11 Newtons at a metre between 2 kilograms. Itís an incredibly tiny force and it wasnít done until near the end of 19th century.
Chris -  Henry Cavendish, wasnít it?
Dave -  Yup. Indeed and you can work it out, and then from that, you can work out how heavy the Earth is, and from that, how heavy everything else is in the universe really.
Click to visit the show page for the podcast in which this question is answered. Alternatively, listen to the answer now or [download as MP3]
« Last Edit: 10/12/2010 15:26:06 by _system »
 

Offline CPT ArkAngel

  • Hero Member
  • *****
  • Posts: 586
  • Thanked: 4 times
    • View Profile
How much does the Earth weigh?
« Reply #20 on: 01/12/2010 04:24:22 »
For me, the weight of the earth is equal to mine. I can feel it right now... ???

The weight is a force : F = m * g
« Last Edit: 01/12/2010 04:26:25 by CPT ArkAngel »
 

Offline Foolosophy

  • Sr. Member
  • ****
  • Posts: 218
    • View Profile
How much does the Earth weigh?
« Reply #21 on: 01/12/2010 08:43:16 »
(is the earth accelerating around the sun? so from your own Newtonian equation a=0 so F=0,)

The earth is by definition in free fall motion/orbit around the sun

The earth's weight is therefore equal to zero = ie its like being in a weightless environment

The mass of the earth is an intrinsic property of the earth and is constant

(although relativity tells us that mass itself is subject to relativistic effects - for example, the rest mass is different from when the same body is moving - but thats another thread topic)

 

Offline imatfaal

  • Neilep Level Member
  • ******
  • Posts: 2787
  • rouge moderator
    • View Profile
How much does the Earth weigh?
« Reply #22 on: 01/12/2010 10:11:17 »
Foolosophy - yes the earth is accelerating (it's in circular motion; it must be accelerating) a≠0 F≠0.  I agree with the Arkangel - although I think it weighs as much as me rather than as much as him
 

Offline Foolosophy

  • Sr. Member
  • ****
  • Posts: 218
    • View Profile
How much does the Earth weigh?
« Reply #23 on: 01/12/2010 11:02:11 »
do you know why there is weightlessness on an orbiting satellite?

Answer that question and you will understand why the weight of the earth is equal to zero

Weight is a different concept to Mass

(as far as your claim that the earth is accelerating you must remember that acceleration is the change in velocity (ie dv/dt)

how is the earths velocity changing?)
« Last Edit: 01/12/2010 11:04:34 by Foolosophy »
 

Offline Foolosophy

  • Sr. Member
  • ****
  • Posts: 218
    • View Profile
How much does the Earth weigh?
« Reply #24 on: 01/12/2010 12:14:28 »
Foolosophy - yes the earth is accelerating (it's in circular motion; it must be accelerating) a≠0 F≠0.  I agree with the Arkangel - although I think it weighs as much as me rather than as much as him

So you are claiming that the earth's velocity is changing??

what is driving this dv/dt and in what direction is it occuring?

 

The Naked Scientists Forum

How much does the Earth weigh?
« Reply #24 on: 01/12/2010 12:14:28 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums