Force of Permanent Magnets when affected by Temperature & Distance
Introduction: Magnets are used today in our everyday life. We use them for:
- Cabinet Latches
- Hanging Pictures on Different Surfaces
- Electric Motors
- Electromagnetic power devices: TVs, VCRs, Cranes, Fax and Printing Machines
- Medical Field: MRIs
- Transportation: Cars, Subways, Cable Cars, Elevators
They are the building blocks of some of the great technology that exists today. The above list of uses, is just some of the ways that magnets are used but there is still an important magnet that is missing and that is the Earth. The earth is a giant magnet. The picture below shows the earth and its magnetic field.
Currently there are three main types of magnets:
- Temporary magnets which are self explanitory. Once it is attached to a strong magnet the magnetism is lost. Hence the word temporary.
- Permanent magnets which are magnets that retain there magnetism.
- Electromagnets which are temporary magnets but are produced by an electric current.
This experiment will focus on permanent magnets.
Equipment:
- 10 Permanent Magnets
- Water Bath
- Thermometer
- Force Probe
- Magnetic Field Probe
- Logger Pro
- 100 Large Paper Clips
- Plastic bowl
- Yard Stick
- Tape
- Glue
Experimental: My experiment was to test the force of permanent magnets under certain conditions such as: temperature and distance. I completed three different experiments to show how force is affected.
- I measured the force vs. the distance. To due this, I used a force probe and the computer program logger pro. I set down a yard stick that had units of centimeter down on a table and then taped a permanent magnet at the end of the yard stick and recorded the results of the force at each centimeter up till 5 cm.
- I measured the magnetic field strength vs. the distance. I did this the same way as my first experiment but I used a magnetic field probe instead of a force probe.
- I measure the force vs. the temperature. I did this by using a water bath that could be set at constant temperatures. I then would allow the magnet to equilibrate in the water for 15 min. at intervals of 10 degrees Celsius, starting at 0 degrees Celsius. At this point, I would then place the magnet inside a bowl that contained paper clips. Those paper clips that were attracted were then counted in order to get an idea of the force present.
- I calculated the magnetic dipole moment and plotted it along with the force vs. the distance. To due this, I used the equation of M = Constant/r^3, where r is the distance and M is the dipole moment. The constant used was .58 the range of r was 1-6 cm. This was all done on excel using the excel formulas to solve the equation. The actual equation is in the link below. Most of the variable can be taken out since the magnets were directly in line with one another.
Dipoles!