??: ???????????????(Simple Harmonic Motion- SHM )

1
??7 ???? (????9)

• ?? ???????????????(Simple Harmonic Motion- SHM )
• ?? ??????(x)??, ???????(Hooks law)
• ??? Fr -kx -kxx (k ????(spring
  constant), x ? x/x)
• ???? U kx2/2
• ?????ms 0 (ms ltlt ????m)
• md2x/dt2 -kx (???????)
• x(t) Asin(k/m)1/2t f Asin(?t
  f)
• ???(angular frequency) ? ? 2?f ?(k/m) rad/s
• ??(amplitude) A
• ??(period) T 1/f
• ??(phase) f
• ????? ms ? 0
• ? k/(m ms/3)1/2

2
?? ??????????????? ?????III 1. ????????k
A ??(static)?? ?????(m1)????,
???, ???y1 ?? F F1 Fr m1g - ky1
0 k(static) m1g/y1
(?????????) B ??(dynamic)??
?????(m1)????, ??y2?????(??A y2 - y1)
?? T 2p?(m1/k)
k(dynamic) 4p2m1/T2 (???????)
(ms???) (7-2)
3
2. ????(coupled oscillation) ????
??(m)????????(k1,ms1),(k2,ms2)????
???????????????, ???(???, ????) md2x/dt2
- k1x - k2x -(k1 k2)x ?????? k k1
k2 ?????? U (k1 k2)x2/2
A. ??????(???)m ???T?m??? B.
???/??????k ?T?k??? C. ????A
?T?A??? D. ???v(t)???x(t)??? E
mv2/2 kx2/2 constant (??????) (7-3)