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AP® Physics 1 & 2

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Moderate

Induced Magnetic Fields: Bar Magnet and Ball Bearing

APPH12-ZNZ5EE

A steel ball bearing is released near the north pole of a bar magnet. The ball bearing starts to roll toward the north end of the magnet. Before it touches the magnet, a student picks up the ball bearing. The student then releases the ball bearing from rest near the south pole of the bar magnet.

Which statement below best predicts what will happen to the steel ball bearing and explains why?

A

It will roll away from the bar magnet’s south pole because the steel ball bearing is a south magnetic pole and opposite poles repel.

B

It will not move at all because the steel ball bearing is repelled from the south pole just as much as it is attracted to the north pole.

C

It will roll towards the south pole because the magnetic domains in the steel ball bearing will realign with the bar magnet’s magnetic field and cause attraction between the two objects.

D

One cannot predict its behavior because the student might have rotated the ball bearing in their fingers before they set it down near the south pole of the bar magnet.