Post on 20-Jan-2016
Videos of classroom physics demonstrations
F. Frising, P. Thiry and R. Sporken
Department of PhysicsUniversity of Namur (FUNDP)Rue de Bruxelles 61B-5000 Namur Belgium
The « Foucault pendulum »
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The « Foucault pendulum »
t = 0 t1
t = 0v
co r r = 0
F = 0
F corF
FF cf F rea lF rea l
F cf
v r
The real Foucault pendulum
Precession rate in Belgium =1 degree in 5
minutes
T = 24 h / sin, the latitude
Trajectories in rotating frames
x , (T = 1s)
, (T = 1s)
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Trajectories in rotating frames
F cor
F cor
F corF
F
F
F cf
F cf0 .3 m
Fcf v r
v r
v in it
v r
x , (T = 1s)
, (T = 1s)
The map of the world
The gyroscope
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The gyroscope
L m g
r
p
= 14.4 s-1
I = 0.0191 kg m2
L = 0.275 kg m2 s -1 r = 0.053 mm = 0.150 kgTp = 2L/(mgr) = 22 s
Tp exp = 26 s
The Maxwell wheel
, L, = r x T x
m g
r
RT
m gr
T
, Lx = r x T
The ring is falling down.
The ring is climbing up.
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The Maxwell wheel : time measurement
2
2
down
R2h 1rt
g
8.1 s
R = 0.0575 mr = 0.0028 mh = 0.76 m
For a ring :
texp = 7.7 s
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The Maxwell wheel : the ring and the disk
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