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        riddles >> what happened >> How to weigh your own head?
        
(Message started by: wonderful on Jun 4^th, 2008, 8:22pm)

Title: How to weigh your own head?
Post by wonderful on Jun 4^th, 2008, 8:22pm

The above question has been discussed in a number of forums. However, it seems that there has been no convincing solution sofar.

Can you suggest a solution?

Have A Great Day!

Title: Re: How to weigh your own head?
Post by cheesepuff on Jun 4^th, 2008, 8:44pm

You could always cut off your head and put it on a scale ;D

or you could just take an exact measure amount of bone, flesh, blood, brain, etc of you brain and add it up accordingly

Of you could cut off someone else's head and weigh it, and then compare the size linearly with the sizes

Or you could just lie down and put your head on a scale, then knock yourself off so your muscles can no longer interfere with your measures

Title: Re: How to weigh your own head?
Post by black_death on Jun 4^th, 2008, 9:29pm

immerse yourself in water such that only your head is above water .... ::) ::)

well on second thoughts this solution is wrong .... so kindly ignore ;D

Title: Re: How to weigh your own head?
Post by Jigsaw on Jun 4^th, 2008, 9:59pm

on 06/04/08 at 21:29:22, black_death wrote:

immerse yourself in water such that only your head is above water .... ::) ::)

I found this in wiki (http://en.wikipedia.org/wiki/Buoyancy).

Quote:

The net upward buoyancy force is equal to the magnitude of the weight of fluid displaced by the body.

Now do as Black Death has told. Place the weighing machine inside the water, stand on it such that only your head is above the water's surface and note down the reading as your apparent weight. ~~The weight of your head is equal to the difference of your actual weight and the apparent weight just found.~~ [edit] You can't find it this way.[/edit]

Title: Re: How to weigh your own head?
Post by towr on Jun 5^th, 2008, 12:39am

on 06/04/08 at 21:59:02, Jigsaw wrote:

Place the weighing machine inside the water, stand on it such that only your head is above the water's surface and note down the reading as your apparent weight. The weight of your head is equal to the difference of your actual weight and the apparent weight just found.

The body has almost the same density as water (it differs per person, and most people do sink). Which means the body is almost weightless in water. And that in turn means that if you take the actual weight minus the apparent weight, you get almost the weight of the body minus the head (but not quite, it may be one or two heads off, I reckon).

I can find the buoyancy of the head, or body, or weight of body+head, but I don't see how to get either head or body by itself. Approximating those by their buoyancy would be inaccurate. Unless perhaps you have reliable data for heads to relate buoyancy and weight. (But then we're back to cutting people's heads off; well, at least it's not your own.)

Title: Re: How to weigh your own head?
Post by Jigsaw on Jun 5^th, 2008, 1:37am

Assume your body has uniform density(d). Find the volume of your body( Volume(v1) of water displaced by immersing yourself completely in it). Now find the volume(v2) of the water displaced with only your head above the water surface. The volume occupied by your head is v1-v2. Density of your body d= W/v1.
Weight of your head= (v1-v2)*d.
I've a feeling that something's wrong.

Title: Re: How to weigh your own head?
Post by towr on Jun 5^th, 2008, 1:42am

on 06/05/08 at 01:37:56, Jigsaw wrote:

I've a feeling that something's wrong.

Just the assumption that body has uniform density. But it'll give a decent approximation, I think.

Title: Re: How to weigh your own head?
Post by black_death on Jun 5^th, 2008, 4:46am

on 06/05/08 at 01:37:56, Jigsaw wrote:

thats what i also initially thought ... but i feel that water displaced will be same in both the cases

Title: Re: How to weigh your own head?
Post by ssa on Jun 5^th, 2008, 5:44am

chop off your twin's head and put it on a scale.

Title: Re: How to weigh your own head?
Post by ThudanBlunder on Jun 5^th, 2008, 6:02am

on 06/05/08 at 05:44:50, ssa wrote:

chop off your twin's head and put it on a scale.

Hey, that's not nice! Anyway, your twin might annoyingly point out that it should be your head.
I have a better idea:
Get a nice, head-shaped bucket and put it on a weighing scale. Note how much the bucket weighs.
Now nip out to the shops and buy a guillotine.
Stick your head through the guillotine, note where your head would fall, and mark this spot carefully with chalk.
Position the bucket and scale on said chalk mark while marvelling at your own foresight.
Finally, stick your head through the guillotine and pull the switch, confident in the knowledge that you have thought of everything.

Neat, eh?

I'm sure your twin will be happy to do the sums.

Title: Re: How to weigh your own head?
Post by Jigsaw on Jun 5^th, 2008, 6:28am

on 06/05/08 at 04:46:45, black_death wrote:

thats what i also initially thought ... but i feel that water displaced will be same in both the cases

No, it isn't the same, as vol(man)+vol(water) should remain constant(considering other factors as being constant).

Title: Re: How to weigh your own head?
Post by Frumious Bandersnatch on Jun 5^th, 2008, 9:35am

Go to your local butcher and ask him, "If my head were veal, which I know that it is not, how much would it be worth?" Then divide his answer by the price of veal per pound to get the weight of your head in pounds.

Title: Re: How to weigh your own head?
Post by Grimbal on Jun 5^th, 2008, 1:35pm

Is the blood in the head part of the head?

Anyway, a neighbor told me that he has been scanned from the head to the feet and the machine gave back a full breakdown of how much muscle, fat and bone he had*. The total weight was within 100g of his real weight. It would be easy for that software to give the weight of the head only.

* I don't know where the brain fits in.

Title: Re: How to weigh your own head?
Post by cheesepuff on Jun 5^th, 2008, 1:44pm

In the old posts, did anyone know the answer or the poster himself had no clue either?

Title: Re: How to weigh your own head?
Post by towr on Jun 5^th, 2008, 1:53pm

on 06/05/08 at 13:35:10, Grimbal wrote:

* I don't know where the brain fits in.

It's mostly fat.
I have it on google's authority that the brain is 60% fat. I would guess the other 40% is mostly water. I wonder if brains float.
[edit]Completely forgotten protein there, haven't I. hmm[/edit]
[edit2]And then another site says the brain is 75% water; if you can't even trust random websites on the internet anymore, what is the world coming to?[/edit2]

Title: Re: How to weigh your own head?
Post by wonderful on Jun 5^th, 2008, 8:09pm

FYI, here is a website that discusses the same
question:

http://www.guardian.co.uk/notesandqueries/query/0,,-1244,00.html

Have A Great Day!

Title: Re: How to weigh your own head?
Post by ThudanBlunder on Jun 6^th, 2008, 6:58am

on 06/05/08 at 20:09:21, wonderful wrote:

FYI, here is a website that discusses the same
question:

All the questions and answers posted (and accepted) to that site, used to be available online.
But since they decided to bring out a book of them, we are limited to just one page per section.
The only other source is Guardian Weekly, and only if you subscribe.
Such is the onward march of commerce!

Title: Re: How to weigh your own head?
Post by Iceman on Jun 6^th, 2008, 11:38am

Quote:

How to weigh your own head?

Replace the pillow with the scale.

Title: Re: How to weigh your own head?
Post by Icecalibur on Jun 6^th, 2008, 12:00pm

Iceman! Long time, no see, mon cher! 8)

Title: Re: How to weigh your own head?
Post by Iceman on Jun 6^th, 2008, 12:51pm

I wondered where did I put my talking sword. :P

Title: Re: How to weigh your own head?
Post by thomamat68W on Jul 4^th, 2013, 11:49pm

The only way I know of to weigh one's own head with 100% accuracy is to enter space. Everything is weightless. Finding it's mass however, would be much more difficult.

Title: Re: How to weigh your own head?
Post by swapnilraja1212 on Sep 18^th, 2013, 1:41am

You can do it approximately by the following method: if you assume that the average density of tissue and bone in your head is similar to that in the rest of your body (taken as a whole), then all you need to do is determine the volume of your head, the volume of the rest of your body, and then multiply the ratio of the two by your total body weight. To determine the volume of your head, fill a bathtub up to the rim and carefully immerse yourself in it completely - including your head. Collect the water that spills over the rim and measure its volume. This is the volume of your entire body. Then repeat the exercise, but this time keeping just your head above water. Measure the over spill again, and subtract this from the volume of over spill on the previous occasion. The amount remaining is equal to the volume of your head. Now take the ratio of the volume of your head alone, divided by the volume of your entire body. Multiply your total body weight by this number. The result is the weight of your head.

Thanks

Title: Re: How to weigh your own head?
Post by alien2 on Sep 19^th, 2013, 1:43am

Archimedes' principle, eh?

Title: Re: How to weigh your own head?
Post by martinly on Dec 2^nd, 2013, 1:31am

on 06/04/08 at 20:44:06, cheesepuff wrote:

cut off your head and put it on a scale ;D

=))))))))) anyone dare to try?

Title: Re: How to weigh your own head?
Post by erica on Jan 25^th, 2014, 4:01am

I found this thread interesting!

Title: Re: How to weigh your own head?
Post by Dufus on Apr 3^rd, 2014, 12:44am

I think to weigh one's head we have to [hide]make the rest of the (headless) body weightless.[/hide] I think buoyancy cant address this aspect.