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Predavanje 1 - phy

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GUŠENE OSCILACIJE<br />

Realne situacije, u kojima postoje disipativne sile!<br />

Npr. trenje - amplituda titranja se smanjuje u<br />

vremenu<br />

Ovo smanjenje se naziva prigušeno titranje<br />

H.O. s trenjem koje je proporcionalno brzini:<br />

∑F x<br />

= −kx − bv x<br />

Jednadžba gibanja:<br />

−kx − bv x<br />

= ma x<br />

tj. - kx - b dt<br />

dx = m d 2 x<br />

dt 2<br />

Rješenje:<br />

x = Ae − ( b 2m)t<br />

cos ω′<br />

t + φ<br />

ω ′ =<br />

k<br />

m − b2<br />

4m 2<br />

( )<br />

Monday, March 14, 2011

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