How do they keep all the raisins in cereal boxes from falling to the bottom?
The Rule of popcorn physics states that unpopped popcorn kernals will fall to the bottom of the bowl.
They put two scoops in
It’s magic.
You’re not supposed to ask.
Actually Sunrise, I know you are bit new but the people here really do know everything. Like you, I don’t like search-engines because I am lazy and would like someone else to do the work for me. There was a thread on this very topic several weeks ago. The answer is:
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Cereal companies know the rate at which raisins will fall to the bottom of the box.
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They fill the bottom portion of the box with plain cereal and the upper part of the box with cereal mixed with raisins.
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As the laws of physics predict, the raisins from the top mix with the cereal in the bottom.
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There is enough restistance from the cereal so that all of the raisins do not end up at the bottom.
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The cereal companies know how to do this through loads of experience and experimentation.
Like I said, I believe that someone on this board actually called the companies to find this out. We will wait for a site because I am to lazy to do so.
The Master’s take on Why don’t the raisins in Raisin Bran all wind up at the bottom of the box?
Cecil’s answer is not quite right. The average density has nothing to do with it, it’s all in the mechanics of sifting. Consider this experiment:
Take a container and fill it about 1/4 full of .5 cm styrofoam balls. Add a layer of 2 cm diameter lead balls and then top it off with another layer of styrofoam balls equal to the bottom layer. Vibrate the container for a while (as would happen while shipping). Where do the lead balls migrate to, the bottom or the top?
It turns out that they migrate to the top[sup]1[/sup]. The density of the balls is irrelevent, the size is all-important. Big things end up on top, little things on bottom.[sup]2[/sup]
So all the raisin bran makers need to do is to have the average size of the flakes be about the same as the average size of the raisins. The raisins will stay mixed. Of course, they may not do this, so then mavpace’s answer will then be correct.
[sup]1[/sup] I should note that with something really heavy like lead balls, you would need to vibrate the container more vigorously or for a longer time than for something lighter, say marbles.
[sup]2[/sup] I’ve actually made use of this behavior at times, although I can’t remember off-hand exactly what for.
>> The density of the balls is irrelevent, the size is all-important
I am not sure I can believe this in such absolute terms. I would have to see the lead balls move up to believe it.
And speaking of lead balls…
Years back, I seem to remember reading on a Raisin Bran (or Raisin Bran knock-off) box to shake before opening. I definitely still shake it today.