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suntrack2
2006-Apr-13, 04:42 PM
in the low gravity if I want to shape one rod for that I have to bit that rod by the hammer, the normal force for this object if I do on the earth it will come down forceably on that rod, means the force will not bare any barrier for hitting that rod, but if I do it on moon in the low gravity, hammer in my hand will come slowly and it will take long time to shape that rod, and for plenty of time I will have to repeat this action on moon, means for a 5 minute work to do on earth it will take some 4 times more time to do the work.

2. if I thrown out the water from my glass in the moon's sky, the action of falling drops on the ground will be half of the falling drops on the earth if I do it?


sunil

tony873004
2006-Apr-13, 04:49 PM
The majority of the force is from your own muscles, not gravity. As you lift the hammer, you give it potential energy and as it strikes the rod, it is all kinetic energy. But that is if you simply let the hammer drop onto the rod. That would take a long time, even on Earth. Your own muscles provide most of the velocity of the hammer so it would be almost as efficient on the Moon. Just my guess.

ToSeek
2006-Apr-13, 04:53 PM
I would go along with what Tony said: you don't drop a hammer onto a nail, you drive it with your arm. The lower gravity won't make a significant difference.

Eta C
2006-Apr-13, 04:58 PM
And, since its mass is the same, the hammer would have the same momentum and kinetic energy and impart the same impulse to the nail on both the Earth and Moon.

suntrack2
2006-Apr-13, 05:14 PM
and if I pressed one spring by applying a a big force in the low gravity, will it bounce back double than on the earth if I press the same.

ToSeek
2006-Apr-13, 05:16 PM
Yes, the spring will bounce higher due to the lower gravity, presumably six times higher since the gravity is 1/6 of the Earth's.

suntrack2
2006-Apr-13, 05:36 PM
thanks toseek, for the answer.

well If the water falling from the nigara waterfall say at the speed of 100kms per hour, and if the same nigara waterfall falling on the surface of the moon in the low gravity, will its falling water will create low noise and lower water back-ups. ?

George
2006-Apr-13, 06:13 PM
If the water falling from the nigara waterfall say at the speed of 100kms per hour, and if the same nigara waterfall falling on the surface of the moon in the low gravity, will its falling water will create low noise and lower water back-ups. ?
Think about what causes the noise. You seem to know already. [Assuming you, somehow, have an equivalent atmosphere that can carry the sound equally.]

Regarding back-up, think about how water would flow with less gravity. Compare the upstream flow rate to the downstream flow rate.

Bob
2006-Apr-13, 11:02 PM
There won't be a waterfall because water can't exist as a liquid in the vacuum at the moon's surface. So there won't be any noise because (a) there isn't any water and (b) there isn't any atmosphere for propagation of sound waves.

suntrack2
2006-Apr-17, 11:57 AM
no, bob it was just for suppose, I was trying the examples.

neilzero
2006-Apr-17, 12:56 PM
Suppose the moon is exactly like Earth except 1/6th gravity: the water at the bottom of the falls will splash with 1/6 the KE, this will reduce the sound by 1/6 or more. I think the low gravity will not effect how the sound propagates nor how your ear hears it. The low gravity will have only minor effects on how you use hammers, screwdrivers, axes, shovels and many other tools. Your footing will however be less secure as you push downward on various tools, and you feet may occasionlly leave the ground. You will have to push down on rakes, saws and plows. Neil

Arneb
2006-Apr-17, 01:04 PM
One minor point: Working wouldn't bequite the same. As counterweight to the force exerted, for exampl, by a hammer hitting a rod we tend to rely on gravity. We would have to work without that on the Moon and look for other possibilities to keep us fixed.

It seems to me that you can see this effects in some of the Videos from the Moon: The astronauts behave differently. Where on Earth simply holding an instrument (was it a core drill?) to the ground firmly with your arm, the apollo astronauts had to lean over and put their entire (reduced) weight) on the instrument to keep it fixed. That sometimes made for nice slapstick when they lost balance and fell over doing what would have seemed a trivial task on Earth.

So: Yet another nail (literally) in the coffin of the HB theories.

Lord Jubjub
2006-Apr-17, 02:59 PM
A sledgehammer relies much more on gravity. Wouldn't a person have to put much more muscle into driving it on the moon than on Earth?

As far as a waterfall on the moon, what would such a feature look like if it were part of an artificial habitat?

Kaptain K
2006-Apr-17, 06:29 PM
A sledgehammer relies much more on gravity. Wouldn't a person have to put much more muscle into driving it on the moon than on Earth?
I think it would be pretty much of a "wash". The extra energy needed to drive it would be compensated by the lesser energy needed to lift it in the first place.

George
2006-Apr-18, 02:23 AM
Suppose the moon is exactly like Earth except 1/6th gravity: the water at the bottom of the falls will splash with 1/6 the KE, this will reduce the sound by 1/6 or more.
I like your thinking, but check the math. v = gt. A 1/6th reduction in gravity will lower the velocity by how much, and what will this do for the KE value?

Tog
2006-Apr-18, 07:42 AM
Wouldn't there also be the lack of air resistance, and the increased resistance from the space suit to consider? I thing that swinging something like a sledge hammer would throw the user off their feet a good portion of the time. At least until they learned how to manipulate it.

George
2006-Apr-18, 01:36 PM
Wouldn't there also be the lack of air resistance, and the increased resistance from the space suit to consider?
We are assuming an equal atmosphere to Earth.


I think that swinging something like a sledge hammer would throw the user off their feet a good portion of the time. At least until they learned how to manipulate it.
Arneb sorta hit on this in his post. For every action, there is a reaction. When your body accelerates the hammer downward, you will feel an equal and opposite force (upward). Since the force from gravity is 1/6, you will feel much different, no doubt, and probably become unbalanced. If you apply a force on the hammer greater than 1/6th your earthly weight... off you go. For a 180 lb. person, only >30 lbs. of force will be required.