When you carry a heavy load such a pail of water with one arm why do you tend to hold your free arm horizontal

Question

Please answer it comprehensively with proofs, please.. Thank you!

Answer 1

so the water genie can climb out of the pail and run up your arm to glide away to her fairy kingdom.

proof:
pail of water + genie
genie on arm
jump genie.
fly away.

Answer 2

In essence, your arms are levers, and the longer the lever, the more force it produces when the same weight is placed on the end of it. In this case, a lever is longer when it is further from your body. You arm doesn't actually need to grow =)

It is like a teeter-totter, the heavy side is shorter than the light side if it is to balance, You arm is lighter than your other arm plus the pail of water, so it has to be longer.

Try this - take a ruler, and tape a couple of pencils around the eight inch mark, and balance it on your finger. Then slide the pencils to the end, and it will not balance anymore, at least not at the same point.

Answer 3

I will answer this shortly from my own knowledge, well!!, thinking of your body as a pivot, will answer your question. Because, when you use one arm to carry a heavy load, the other hand will patently act as an effort, which in particular, will try to equalize the load that is carried by the other arm, and the human body will act as the pivot.
I was thinking the same question and i tried to prove it by trying to carry different weights and the opposing arm will move horizontally depending on the weight you carry.
So the reason that you hold your free arm horizontal is because that it is like a reflex, and that it helps you to carry it properly. Hope you do understand. Thank you.

Answer 4

It has to do with equivalent moments. This sounds like something you'd talk about in a statics class. Basically, the heavy weight in one hand is pulling you in one direction, and the weight of your extended arm is pulling you in the other direction. The weight of your extended arm is less, but it is farther from your body, so it helps to balance the moment the heavy bucket, which is closer to your body, is creating. You can look the equations up in your book.

Answer 5

We do this for balance. The weight of the bucket is partially compensated for by the outstretched arm. The further the arm stretches the more weight is compensated for. Simple leverage laws apply here.

Answer 6

It's just your body's way of trying to compensate for the weight being all on one side of you.If you want proof-watch someone carry a pail of water.

Answer 7

To offset the weight of the pail and balance yourself.

Answer 8

Balance?

Answer 9

I would say this is more of a statics problem. You're shifting your center of mass by holding your arm out, and by swinging it up and down you can give a little extra torque when needed (say, if you have to lift it up onto something).

Answer 10

yes i do but i don't know why. i think because i am trying to off-set the load of the pail of water.