# Is 100kg of stones heavier than 100kg of cotton? Why? How?

Discussion in 'Jukwaa la Elimu (Education Forum)' started by Pape, Sep 14, 2010.

1. ### PapeJF-Expert Member

#1
Sep 14, 2010
Joined: Dec 11, 2008
Messages: 5,536
Trophy Points: 0
...

2. ### Nyani NgabuPlatinum Member

#2
Sep 15, 2010
Joined: May 15, 2006
Messages: 63,774
Trophy Points: 280
I think it may have to do with density and stuff...

3. ### Steve DiiJF-Expert Member

#3
Sep 15, 2010
Joined: Jun 25, 2007
Messages: 6,412
Trophy Points: 145
From little I can remember about physics, I would say, 100kg of stones is equal to 100kg of cotton as far as the weight is concerned.

However, the measurement in mass of the two objects would not be equal, so is their densities and volumes.

4. ### KirangaJF-Expert Member

#4
Sep 15, 2010
Joined: Jan 29, 2009
Messages: 34,057
Trophy Points: 280
A kilogram is a kilogram, and it doesn't matter whether you are talking about a kilogram of stones or cotton.

On the other hand, a pound of gold is not the same as a pound of feathers. A pound of feathers is heavier than a pound of gold.

5. ### Steve DiiJF-Expert Member

#5
Sep 15, 2010
Joined: Jun 25, 2007
Messages: 6,412
Trophy Points: 145
Kiranga, the pound you're talking about is it the imperial unit of weight?! If so, why should the two have different weights?!

6. ### MtazamajiJF-Expert Member

#6
Sep 15, 2010
Joined: Feb 29, 2008
Messages: 5,972
Trophy Points: 0
Explanation kwa kumbukumbu za physics ya form1 1 ni kuwa Density= Mass/Volume

Volume nadhani kwa kiswahili ni ujazo. Kwa mfano rahisi ni kuwa

utahitaji ujazo mkubwa zaidi kuweka pamba ya KG 100 kuliko ujazo utakaohitajika kuweka maweya kg 100. Ndo kusema Uzito( Mass) ni sawa lakini kinachofautisha ni ujazo.

kwa fomula hiyo realistic assumption itakuwa hivi
Kg 100 za mawe be zita occupy ujuzo wa cubic centimer 5. Kwa hiyo density yake= 20Kg/cubic
Pia kg 100 za pamba may be zita occupy ujaz wa cubic centimer 20 . Kwa hiyo density ya pamba itakuwa 5kg/cubic centimeter

Kwa hiyo Mawe ni denser than Pamba but not heavier.

Sijui kama niko sawa.

7. ### PapeJF-Expert Member

#7
Sep 15, 2010
Joined: Dec 11, 2008
Messages: 5,536
Trophy Points: 0
hapo kwenye red bado sijakusoma. Roughly, 0.5 Kg = 1 lb (pound), kama hivyo ndiyo.....inakuwaje 200 lb ya mawe isiwe sawa na 200 lb ya pamba wakati kg na lb ni vipimo vya uzito?

8. ### NjaaJF-Expert Member

#8
Sep 15, 2010
Joined: Dec 6, 2009
Messages: 883
Trophy Points: 60
yes there is little different between mass and weight, weight determined by gravitational pull (weight = mass x gravity force(g)), but (mass = density/volume). According to the formula of weight, then 100kg of stone and 100kg of cotton they should have the same weight provided that the measurement is taken at the same place. The value of gravity force decreases as you away from the Earth surface, Hence if the measurement is taken on the moon surface then both will have the same weight because g is the same.

My conclusion is, 100kg of stone and 100 kg of cotton they have the same mass every where, and they have the same weight in the same altitude.

9. ### E=mcsquaredJF-Expert Member

#9
Sep 15, 2010
Joined: Apr 1, 2009
Messages: 218
Trophy Points: 35
The 2 parcels have essentially the same weight, unless are in different positions of the earth's surface where gravitation due to acceleration differs significantly, short of which some recent recent experimental evidence showing otherwise should be given, and possibly backed up by a Nobel Prize award in Physics.

However, if only their masses are observed using a naked eye, one may apparently conclude the opposite of the blinded assertion as presented here.

10. ### KirangaJF-Expert Member

#10
Sep 15, 2010
Joined: Jan 29, 2009
Messages: 34,057
Trophy Points: 280
A pound of feathers is heavier than a pound of gold because gold is measured in troy pounds, while feathers are measured in avoirdupois pounds.

Troy pounds have 12 ounces; avoirdupois pounds have 16 ounces. A Troy pound contains 372 grams in the metric system; an avoirdupois pound contains 454 grams in the metric system, therefore each troy ounce is heavier than an avoirdupois ounce, making a pound of feathers heavier than a pound of gold.

Don't blame me, blame the English.

11. ### ButolaJF-Expert Member

#11
Sep 15, 2010
Joined: Jan 19, 2010
Messages: 2,140
Trophy Points: 0
Usahihisho kidogo; Mass = Density x Volume;
Weight= Mass x Acceleration due to Gravity;

12. ### MtazamajiJF-Expert Member

#12
Sep 15, 2010
Joined: Feb 29, 2008
Messages: 5,972
Trophy Points: 0
Tumia SI unit zinazoeleweka kwa wengi. Au mwenzetu toka O Level ulikuwa ushaenda kwa malkia.

13. ### KirangaJF-Expert Member

#13
Sep 15, 2010
Joined: Jan 29, 2009
Messages: 34,057
Trophy Points: 280
"SI unit zinazoeleweka " ndiyo kitu gani ? Unaniambia nitumie standards wakati wewe mwenyewe hujui kufuatisha standards?

Halafu kwa nini unalazimisha nitumie standard fulani ? Who died and made you chief in here ?

Unaweza kufuatilia mada? Mbona nilishajibu kwali katika SI units hapo juu?

Au unataka kupamia tu ?

14. ### Ng'wanangwaJF-Expert Member

#14
Sep 15, 2010
Joined: Aug 28, 2010
Messages: 9,408
Trophy Points: 160
In terms of weight, both are equal (because weight is determined by g = 9.81kgF. And this is applicable for both stones and cotton, but in terms of mass there must be a difference because by definition mass of an object is the quantity of matter it contains.

A stone has its particles more compacted than that of cotton. Consequently, 100kg of stone will occupy little space than that of cotton.

Little space means lower volume occupied and therefore high density for 100kg of stone than 100kg of cotton.

15. ### KirangaJF-Expert Member

#15
Sep 15, 2010
Joined: Jan 29, 2009
Messages: 34,057
Trophy Points: 280
How do you measure mass ? What SI Units do you use to measure mass ?

The question is "which is heavier", and we are already given the respective kgs, so density and volume do not figure prominently as you suggested.It is not like we have to use density and volume to find the kgs, we have the respective kgs already.

The question is essentially, which is heavier 100 kg or 100 kg ?

The "cotton" and "stones" aspect of the question is introduced to give a psychological illusion, because people would associate stones with heavy and cotton with light, but as long as they are both 100kg, there is no difference in heavyness.

Now had the question been one metre cube of stone vs one metre cube of cotton, with the known average densities of cotton and stones, the higher density of stones (presuming we are talking of average stones with a higher density than that of cotton) would figure and the illusion will become a reality, and one metre cube of stone would be heavier than one metre cube of cotton.

16. ### MtazamajiJF-Expert Member

#16
Sep 15, 2010
Joined: Feb 29, 2008
Messages: 5,972
Trophy Points: 0
Usiwe na jazba Kiranga
SI unit ni Standard Measuremnt Unit.
hayo mambo ya troy pounds na avoirdupois pounds unayoyasema unaweza kuyafafanua kimahesabu? unaweza kufanya conversion zake. Umewai kufanya calcculation ya physics kwenye uzito wa punds?

Ndio maana kukawepo kuna kitu kinaitwa SI unit inayokubalika kimataifa. Ukisema umbali wa kutoka eneo A to B ni yards 600 hiyo siyo SI unit inayokubalika labda kwa hao waingereza

So tell us when u critically challenge others people's ideas, comments and views who died and made u chef?

Hata uki google kitu usichukue kizima kizima kama kilivyo.

17. ### CalvinPowerJF-Expert Member

#17
Sep 15, 2010
Joined: Nov 25, 2008
Messages: 778
Trophy Points: 35
lakini jamaa kaandika 100gk na sio 100kg cheki mwanzo wa thread. g before k means what? hii units siijui may be ya mars

18. ### KirangaJF-Expert Member

#18
Sep 15, 2010
Joined: Jan 29, 2009
Messages: 34,057
Trophy Points: 280
As long as tunaongelea standards, let's keep them.

Hakuna kitu kama "SI Unit zinazoeleweka" either unaongelea "SI Unit inayoeleweka" au "SI Units zinazoeleweka"

Nini SI Units, watu tushaona mpaka galactic units, Kilingon units, negative energy, imaginary time, anti-matter, multiverses, action-at-a-distance spookyness na singularity yenyewe measurements zote zinapovunjika.

Unaniuliza nifafanue na kufanya conversion wakati conversion nishakupa hapo juu? Unajua kusoma wewe?

Unajua hata tofauti kati ya "Chief" na "chef"?

Inaonekana hujui.

19. ### Steve DiiJF-Expert Member

#19
Sep 15, 2010
Joined: Jun 25, 2007
Messages: 6,412
Trophy Points: 145
Duuuh.....!!! umeona yote hayo???! wee mtu unatisha kwelikweli!!!! )
NN sijui yuko wapi hapa.... can't wait for a skit to this on-stage battle lol

20. ### KirangaJF-Expert Member

#20
Sep 15, 2010
Joined: Jan 29, 2009
Messages: 34,057
Trophy Points: 280
Wewe kwa kushabikia tu, ushaona saa inayokwenda anti-clockwise lakini haipotezi uwezo wa kuonyesha majira sawa ?

Watu tushaona mpaka antigravity katika Kaluza-Klein spacetime, na flatworlds zenye multiple time dimensions huyu anatusimangia "SI Unit zinazoeleweka" ?