ball bearing

[ray hampton]

will a bucket of 1/2 " bearing weight the same as a bucket of 1/4" bearing ? both buckets fill to the top

[David Weaver]

Yes, for the most part. There will be a very small difference due to the interaction of the ball diameter with the bucket diameter. That would be a tiny difference, though.

[ray hampton]

I came across this tidbit on the internet and I were taught different when I went to school, too bad I can not gather the bearing to try it

[Rich Engelhardt]

too bad I can not gather the bearing to try itYou might be able to come close enough if it's just to satisfy your curiosity by using some lead shot. See if any of the local gun stores sell bulk shotgun shot. Single aught buck is .60" in diameter - a bit larger than 1/2" and #3 Buck is .25" in diameter. They may let you scoop a couple of bucket of each and weigh them.

[David Weaver]

When the objects are the same shape, everything is proportional. So the proportion of air between the balls stays the same, it just varies exactly proportional to the size of the balls. If the proportion of the bearings to the air space stays the same, then the weight will be the same.

The bucket adds another variable, but when the size of the bucket is large in relation to the size of the bearings, the effect of the bucket is pretty small.

I don't have anything to try it, either, just reasoning through it.

[phil harold]

1/4" should wieght more
there will be less center diameter
the will fit next to each tighter
so there is less air/space in the bucket

[Brian Tymchak]

When the objects are the same shape, everything is proportional. So the proportion of air between the balls stays the same, it just varies exactly proportional to the size of the balls. If the proportion of the bearings to the air space stays the same, then the weight will be the same.


I agree with your last statement. Actually I agree with both. But IMHO, the proportion of total air volume to the total bucket volume is reduced with the smaller balls and, consequently, the bucket will weigh more (assuming of course the balls weigh more than air :rolleyes: and that the 1/2" balls are made of the same exact material as the 1/4" balls..). ..Gotta get all the disclaimers in..

[mike holden]

1/4" should wieght more
there will be less center diameter
the will fit next to each tighter
so there is less air/space in the bucket
Phil is correct.
The concept is known as: "More and more of less and less"
I was originally introduced to the concept with the question: "Which would you prefer? A mason jar filled with quarters? or a mason jar filled with dimes"
(at the time, both quarters and dimes were solid silver)
The writer of the textbook actually filled a mason jar with each and showed the difference in pictures and amounts.
Pretty convincingly, nothing like money to get a young man's attention.
Mike

[Biff Johnson]

will a bucket of 1/2 " bearing weight the same as a bucket of 1/4" bearing ? both buckets fill to the top

I guess that's assuming the both bearings are of the same material and both buckets the same size? Too many variables to give a blanket answer, unlike the "ton of feathers, ton of bricks" analogy.

[Steve Peterson]

Phil is correct.
The concept is known as: "More and more of less and less"
I was originally introduced to the concept with the question: "Which would you prefer? A mason jar filled with quarters? or a mason jar filled with dimes"
(at the time, both quarters and dimes were solid silver)
The writer of the textbook actually filled a mason jar with each and showed the difference in pictures and amounts.
Pretty convincingly, nothing like money to get a young man's attention.
Mike

It should not make any difference if the jar was filled with dimes or quarters and you are only interested in the weight of silver in the jar. Both should pack with equal efficiency, although the smaller dimes might be easier to pack. Dimes supposedly take about 5% more volume than quarters for the same face value, but the ratio of coin vs air should be the same.

The original question about balls seems intuitively obvious that the weight would be the same. You can pack 8 of the 1/4" balls into the same space as one 1/2" ball. The air gaps will be 1/8 times smaller and there will be 8 times as many of them. The best way is to mix the sizes using 1/4" balls to fill the holes between the 1/2" balls, then add 1/8", 1/16", 1/32", etc size balls until there is no space left unfilled.

Steve

[David Weaver]

If the balls stood on top of each other, the answer would be identical, it's obvious because each sphere would occupy a small square. If you then offset the balls so that they fit neatly into the space between the balls on the layer below, big or small, they would both drop a proportional amount of the bearing radius. So where in that does the answer change to smaller is more dense?

[ray hampton]

Phil is correct.
The concept is known as: "More and more of less and less"
I was originally introduced to the concept with the question: "Which would you prefer? A mason jar filled with quarters? or a mason jar filled with dimes"
(at the time, both quarters and dimes were solid silver)
The writer of the textbook actually filled a mason jar with each and showed the difference in pictures and amounts.
Pretty convincingly, nothing like money to get a young man's attention.
Mike

you can add the smaller bearings to the space between the larger bearings if you increase the larger bearing size according, this computer went off -line three days this week while I was typing a post, I thought that it could be cause by a storm but not this many times in one week, the cable company that provide my service switch hands and I now think that they are causing the trouble by throwing a switch

[ray hampton]

It should not make any difference if the jar was filled with dimes or quarters and you are only interested in the weight of silver in the jar. Both should pack with equal efficiency, although the smaller dimes might be easier to pack. Dimes supposedly take about 5% more volume than quarters for the same face value, but the ratio of coin vs air should be the same.

The original question about balls seems intuitively obvious that the weight would be the same. You can pack 8 of the 1/4" balls into the same space as one 1/2" ball. The air gaps will be 1/8 times smaller and there will be 8 times as many of them. The best way is to mix the sizes using 1/4" balls to fill the holes between the 1/2" balls, then add 1/8", 1/16", 1/32", etc size balls until there is no space left unfilled.

Steve

at long as the bearings are round, there will be empty space between each bearing, the solution are to fill the bucket with the bearing then add sand and shake the bucket to pack the sand-down so that the sand will fill the space between each bearing then you can add hot water to the bucket to fill the space between each grain of sand

[ray hampton]

You might be able to come close enough if it's just to satisfy your curiosity by using some lead shot. See if any of the local gun stores sell bulk shotgun shot. Single aught buck is .60" in diameter - a bit larger than 1/2" and #3 Buck is .25" in diameter. They may let you scoop a couple of bucket of each and weigh them.

this sound like a good idea , many thanks

[Larry Frank]

The packing efficiency of the spheres is about 74.05% and is the same for both larger and smaller sizes.

As someone mentioned, if the bucket is very large, they would weigh the same. For smaller buckets, the smaller bearings would fit the container easier and would be just very slightly heavier.

[David Weaver]

Thanks for putting a number to it. I like to think my intuition and reasoning is never bad (I'm a professional educated guesser, anyway), but it often is!