Jump to content

Quinn's Blog

Sign in to follow this  
  • entries
    15
  • comments
    11
  • views
    2,323

Direction of Magnetism

Quinn

522 views

A tool that provides direction by the use of magnetism is based on the basis of physics. This tool, the compass, has been used for many centuries and helped guide history through various explorations. Today, this tool is not used as much as it had been in the past but if you are ever lost it is a great instrument to help you find your way.

Magnetism is one of the first bits of science students learn about in school and just about the first thing we discover is that like poles repel opposite poles attract. If you hold two bar magnets so their north poles are almost touching, they will push away from one another; if you turn one of the magnets around so one magnet's north pole is near the other magnet's south pole, the magnets will pull toward one another. That's all there is to a compass: the red pointer in a compass - the magnetized needle - is a magnet and it's being attracted by Earth's own magnetism called the geomagnetic field. Earth behaves like a giant bar magnet with one pole up in the Arctic and another pole down in Antarctica. Now if the needle in your compass is pointing north, that means it is being attracted to the Earth's north pole. Since unlike poles attract, the compass is being attracted to must be a magnetic south pole. Furthermore, the thing we call Earth's magnetic north pole is actually the south pole of the magnet inside Earth. Originally this concept was a little challenging to grasp but then I realized all I need to remember is that opposites attract. Earth's magnetic field is actually quite weak compared to forces like gravity and friction. For a compass to be able to show up the relatively small effects of Earth's magnetism, the effects of these other forces must be minimized. That is why compass needles are lightweight and mounted on frictionless bearings.

Compasses provide direction to our destination which in the end can be more useful than most other instruments we use in our daily lives.



1 Comment


Recommended Comments

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Add a comment...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Terms of Use

The pages of APlusPhysics.com, Physics in Action podcasts, and other online media at this site are made available as a service to physics students, instructors, and others. Their use is encouraged and is free of charge. Teachers who wish to use materials either in a classroom demonstration format or as part of an interactive activity/lesson are granted permission (and encouraged) to do so. Linking to information on this site is allowed and encouraged, but content from APlusPhysics may not be made available elsewhere on the Internet without the author's written permission.

Copyright Notice

APlusPhysics.com, Silly Beagle Productions and Physics In Action materials are copyright protected and the author restricts their use to online usage through a live internet connection. Any downloading of files to other storage devices (hard drives, web servers, school servers, CDs, etc.) with the exception of Physics In Action podcast episodes is prohibited. The use of images, text and animations in other projects (including non-profit endeavors) is also prohibited. Requests for permission to use such material on other projects may be submitted in writing to info@aplusphysics.com. Licensing of the content of APlusPhysics.com for other uses may be considered in the future.

×
×
  • Create New...