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WHAT’S HAP
PENING?
HERE'S HOW
1. Tape the needle to the center of the
polystyrene disk. Fill the bowl with
water and float the disk on the water. Be
careful not to let the disk touch the
sides of the bowl.
2. Now move first the north pole and then
the south pole of the bar magnet toward
the needle, and note when the pointed
tip and when the eye of the needle is
attracted.
3. Then place the bar magnet far away and
pay attention to the direction the
needle points after a few minutes.
4. Where does the needle point when the
disk stops moving?
Compare its position with that of the
compass needle.
The sewing
needle shows
the direction
YOU WILL NEED
→ polystyrene disk
→ bar magnet
→ compass
→ tape
→ magnetic needle from
Experiment 6
→ bowl
→ water
The needle alw
ays turns to p
oint
in the same di
rection — eve
n if
you turn the p
olystyrene dis
k to
point the need
le in a differen
t
direction. It’s t
he same direc
tion
that the comp
ass needle po
ints.
So you have b
uilt yourself a
simple compa
ss.
1
2
3
4
24
EXPERIMENT 18
Содержание 665050
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