How does the direction of the stroke affect the which pole the needle is attracted to?

Think of an atom as sugar frosted mini wheat (just like the cereal). The atoms in a piece of metal, before it becomes magnetized, is like when you pour miniwheats into a bowl: they are all scrambled and facing in random directions. When the magnet is rubbed on the needle, it would be as if you took some of the miniwheats in the bowl and you aligned them so that they face the same way. The stronger the magnet that is used to rub the needle the greater number of the atoms, or miniwheats, that will align in the same direction. The stroking direction AND the polarity of the magnet being used will determine which way the atoms, or miniwheats, will end up facing.

How do you figure out which side of the magnet is facing North?

Great question! I think you'll be able to figure it out if you watch this video http://www.khanacademy.org/science/projects/discoveries/magnetism/v/floating-magnet--poles. Brit illustrates how the magnet is labeled! It's a good video as well. I'd answer the question, but I think you'd appreciate being able to see Brit explain how you can do an experiment to see why! Awesome question though.

Well, if the needle points north, then it is the north pole of the magnet(because the geographical north of the earth is the magnetic south). Does that mean the direction we stroke towards becomes the same pole as the pole of the magnet it is stroked with?

The direction the needle is stroked is the direction it will point. but if you stroke it with the south side the needle will point north because opposite forces attract. Does this help?

I have been hearing that the direction in which you stroke matters. Is this true?

Great question. Try out this exercise: https://www.khanacademy.org/science/discoveries-projects/discoveries/magnetism/e/compass-challenge

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Physics library

Course: Physics library > Unit 18

Lesson 1: Discovery of magnetism

Compass build (stroke direction)

Name: Compass build (stroke direction)
Uploaded: 2013-04-26T15:39:03Z
Description: Does the direction which we stroke the needle determine the final orientation?

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Does the direction which we stroke the needle determine the final orientation? Created by Brit Cruise.

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Posted 10 years ago. Direct link to %(username)s's post “How does the direction of...”
How does the direction of the stroke affect the which pole the needle is attracted to?
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(26 votes)
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- Ray
  Posted 10 years ago. Direct link to Ray's post “Think of an atom as sugar...”
  Think of an atom as sugar frosted mini wheat (just like the cereal). The atoms in a piece of metal, before it becomes magnetized, is like when you pour miniwheats into a bowl: they are all scrambled and facing in random directions. When the magnet is rubbed on the needle, it would be as if you took some of the miniwheats in the bowl and you aligned them so that they face the same way. The stronger the magnet that is used to rub the needle the greater number of the atoms, or miniwheats, that will align in the same direction. The stroking direction AND the polarity of the magnet being used will determine which way the atoms, or miniwheats, will end up facing.
  Comment on Ray's post “Think of an atom as sugar...”
  (34 votes)
yingyangbu
Posted 10 years ago. Direct link to yingyangbu's post “How do you figure out whi...”
How do you figure out which side of the magnet is facing North?
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(17 votes)
Answer
- ben m
  Posted 10 years ago. Direct link to ben m's post “Great question! I think ...”
  Great question! I think you'll be able to figure it out if you watch this video http://www.khanacademy.org/science/projects/discoveries/magnetism/v/floating-magnet--poles. Brit illustrates how the magnet is labeled! It's a good video as well. I'd answer the question, but I think you'd appreciate being able to see Brit explain how you can do an experiment to see why! Awesome question though.
  Comment on ben m's post “Great question! I think ...”
  (3 votes)
eightsquare
Posted 10 years ago. Direct link to eightsquare's post “Well, if the needle point...”
Well, if the needle points north, then it is the north pole of the magnet(because the geographical north of the earth is the magnetic south). Does that mean the direction we stroke towards becomes the same pole as the pole of the magnet it is stroked with?
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(2 votes)
Answer
- jaydenodom
  Posted 10 years ago. Direct link to jaydenodom's post “The direction the needle ...”
  The direction the needle is stroked is the direction it will point. but if you stroke it with the south side the needle will point north because opposite forces attract. Does this help?
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  (4 votes)
Vyshnavi
Posted 7 years ago. Direct link to Vyshnavi's post “How do you find out which...”
How do you find out which side of the magnet is facing North?
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(3 votes)
Answer
Alex Sierputowski
Posted 9 years ago. Direct link to Alex Sierputowski's post “What if you stroke half t...”
What if you stroke half the needle to face north and the other half to face south? would it keep spinning or lock into place?
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(2 votes)
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Eric
Posted 9 years ago. Direct link to Eric's post “I have been hearing that ...”
I have been hearing that the direction in which you stroke matters. Is this true?
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(1 vote)
Answer
- brit cruise
  Posted 9 years ago. Direct link to brit cruise's post “Great question. Try out t...”
  Great question. Try out this exercise:
  https://www.khanacademy.org/science/discoveries-projects/discoveries/magnetism/e/compass-challenge
  Button navigates to signup page
  (4 votes)
Victoria
Posted 3 years ago. Direct link to Victoria's post “At 0:29 what is being stu...”
At
0:29
what is being stuck onto the needle?
At
0:19
what is being rubbed on the needle? A magnet?
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(2 votes)
Answer
yaritzasanchez
Posted 8 years ago. Direct link to yaritzasanchez's post “why do magnets like south...”
why do magnets like south and north stick together?
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(2 votes)
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babin26533
Posted 8 years ago. Direct link to babin26533's post “ok so let me get this str...”
ok so let me get this straight, the direction of the stroke affects the needle direction.
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(1 vote)
Answer
- trek
  Posted 8 years ago. Direct link to trek's post “No, the strokes are align...”
  No, the strokes are aligning the iron molecules.
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  (1 vote)
Charles
Posted 9 years ago. Direct link to Charles's post “Why does the needle alway...”
Why does the needle always face north?
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(1 vote)
Answer

Video transcript

(rubbing) (rubbing)