CHALLENGER'S LOST LESSONS - ER - NASA

36Materials:1. Pair of bar magnets and string2. Compass3. A plastic half liter empty clear soda bottle (16 oz.)4. Plastic test tube sized about 3/4 the bottle height and with adiameter capable of allowing item 5’s axle-like insertion intothe test tube.5. A cylindrical magnet for insertion into the test tube, perhaps,a cow magnet or a stack of Radio Shack button magnetsinserted in the tube.6. A roll of masking tape.7. And, of course, iron filings from a science museum orscientific experiment supplier.8. (Optional) video camcorder with flip out playback screen9. (Optional) digital still cameraProcedure:(Optional: Have an assistant video tape the procedure just as Christawas video taped.)The previous photo captures Christa performing a bar magnetdemonstration. This experiment is easily done in a classroom.Before continuing, watch the video clip several times, listeningcarefully to Christa and Bob Mayfield’s comments. (Click herewhile holding the ctrl key down to view the video.)Actually, the video of Christa’s bar magnet grounddemonstration is an excellent learning tool not only magnetism butalso Newton’s laws. Tie a string to the center of one of the barmagnets as shown in the above photo. Next bring like poles in closeproximity, and note the rotation of the hanging magnet about itscenter, suspended from the string. After placing one of the barmagnets on a table, slide the other bar magnet toward it so that likepolescome into close proximity. Assure the pair of magnets arealigned and parallel as shown below.