Physics 110 Problems - My Solutions
Dr. Hulan E. Jack Jr.
Chapter14 Q1
Griffith, W. Thomas; The physics of everyday phenomena: a conceptual introduction for
physics;4th Edition ISBN 0-07-250977-5
THE PROBLEM STATEMENT
Ch14 Q1. The north pole of a hand-held bar magnet is brought near the north pole of a second bar
magnet lying on a table. How will the second magnet tend to move? Explain.
YOU TRY IT HERE FIRST
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Page 1 of 3
Physics 110 Problems - My Solutions
Dr. Hulan E. Jack Jr.
Ch14 Q1. The north pole of a hand-held bar magnet is brought near the north pole of a
second bar magnet lying on a table. How will the second magnet tend to move? Explain.
Definitions, concepts , principles and Discussion
Like poles repel.
Unlike poles attract
FM
FM
N
N
S
a
S
Newton’s 3rd Law of Motion :equal and opposite , action-reaction
Newton’s 2nd Law of Motion F = ma
Discussion
BRAINSTORMING
Page 2 of 3
Physics 110 Problems - My Solutions
Dr. Hulan E. Jack Jr.
Ch14 Q1. The north pole of a hand-held bar magnet is brought near the north pole of a
second bar magnet lying on a table. How will the second magnet tend to move? Explain.
Basic Solution (Minimum Expected from the student)
N
FM
S
FM
N
S
a
N
S
Since like pole repel, they will repel each other. The magnet on the table will be pushed
away.
Or, in more detail.
Like pole repel. By Newton’s 3rd of Motion, they will repel each other with equal and
opposite magnetic force FM . The magnet on the table will be pushed away with an
acceleration a .
By Newton’s 2nd Law of Motion, a = FM /m where m is the mass of the magnet.
BRAINSTORMING
Page 3 of 3