5G20.50 - Iron Rod and Hammer

Code Number:
Demo Title:
Iron Rod and Hammer
Magnetic Forces & Fields
Area of Study:
Electricity & Magnetism
Hammer, Compass, and Soft Iron Rod.

Show that the ends of the rods will attract both the south and the north poles of the compass (random magnetic domain orientation).  Hold the rod on the north/south line with a dip of 60 to 70 degrees and hit the end with a hammer.  As you bring the rod to the compass it should attract one pole of the compass and repel the other (oriented magnetic domains).  To randomize the rod again align it along the east/west line and hit it several times with the hammer.

  • G. Faucher, "Ferromagnetism and the Secret Agent", TPT, Vol. 26, #1, Jan. 1988, p. 30.
  • "B-370. Hammering Iron Bar", DICK and RAE Physics Demo Notebook, 1993.
  • G. D. Freier and F. J. Anderson, "Er-8", A Demonstration Handbook for Physics.
  • Shoma Kutasov, "Magnetization of a Rod in the Magnetic Field of the Earth", Physics Demonstrations, p. 176.
  • Janice VanCleave, "18. Demagnetize", Magnets, p. 72.
  • Rudolf F. Graf, "Magnetism From the Earth's Field", Safe and Simple Electrical Experiments, p. 62.

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