Multimedia approach to Teaching physics T.K. Ng

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Multimedia approach to Teaching physicsT.K. Ng

• SIG Meeting (18-2-2003)

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Motivation

• Physics concepts/ideas are often difficult to
  visualize and understand,
• e.g. Electricity and Magnetism, Relativity..

See you.
Bye bye.
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Example Electric Motor
The basic idea of electric-motor is to pass
current through a coil in a (constant) magnetic
field. A torque is generated on the coil by
Faradays Law ? Coil rotates
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Can students visualize how this work in reality?

• Demonstrations, real experiments...
• Example a self-built electric motor that costs lt
  HK20.

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Problem

• This kind of simple demonstration does not always
  exist.
• Example special relativity (need travel speed
  close to speed of light ...)
• ? multi-media approach for better visualization
  of physics concept.

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Earlier work!

• Create better power-point file
• e.g. relativity

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Bye bye.
See you.
t1
t2
This objection is usually rephrased in the
so-called twin paradox. Suppose there is a pair
of twins on earth. The first one, t1, remains on
earth, while the second one, t2, is sent off in a
rocket ship on a trip to a distant star.
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MaMa!
t1
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t1
30 years later(according to the clock on earth)
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Im back!
The question is, is t1 older than t2? The
reverse? Or do they have the same age?
t1
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No. I see youare moving. Youare younger.
You are moving.You are younger
t1
t2
From the angle of t1, time runs slower in t2
since t2 is moving with respect to earth.
Therefore, t2 is younger. However, motion is
relative, and according to t2, time runs slower
in t1 since the earth is moving with respect to
the rocket! Who is correct?
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Oh! I canfeel it!
The answer to this question lies on the
observation that only motions with uniform
velocities are relative. Motions that involve
acceleration are absolute. A person cannot
detect uniform motion, but he/she can tell
whether he/she is accelerating or not!
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Oh!
Oh!
t1
The motion of the two twins is not totally
relative to one another. In order for t2 to come
back, he has to decelerate to change direction
when returning and also when landing on earth.
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So you are younger.
I see.
t1
t2
Our above analysis is applicable only in an
inertial reference frame, i.e. only applicable to
t1. Therefore, the conclusion of t1 that t2 is
younger should be the correct one. What t2 should
observe is that although the clock of t1 seems to
run slower when he is in uniform motion, he will
find that when he is accelerating/decelerating,
the clock of t1 suddenly run much, much faster.
The net result is that t1 is older when t2
returns to earth.
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Present plan incorporate more powerful
multimedia tools in teaching physics

• Animations, interactive-ness, web-based..
• Long-Term Planning - involve (UG)-students
  (1-credit project course)
• First step DIY workshop in winter
• example of student exercise different phases of
  moon

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End (for present)

• Thank you!