Recent content by blost

so... 2 different theta it's a bit too complicated for me... how i must modificated my solution ?

(distance between bars-d) sory but english is not my first language and... when I put "pin" in my dict there is only "penis" :D Theta is a delfection angle of bar...

ok... I tried do It better: M_1=- \frac{1}{2}d mgsin \theta M_2=-kxcos\theta d \Leftrightarrow M_2=-ksin\theta d cos \theta d M_w=- \frac{1}{2}d mgsin \theta-ksin\theta d^2 cos \theta sin\theta \approx \theta cos\theta \approx 1 M_w=- \frac{1}{2}d mg \theta-kd^2\theta I...

\varepsilon = \frac{M}{I} I=1/3 ml^2 M=F*l F=-kx \Rightarrow F=-ksin\alpha l \varepsilon = \frac{-ksin\alpha l^2}{1/3 ml^2} \varepsilon =-3 \frac{ksin\alpha}{m} I try my best but I think it is wrong...

1) yes, there is some sinusoidal force but I think we can forget it. I needed it to second part of task... I have no idea how to do it... I Must write some differential eguation, yes ? I still have big problems with differential equations...

so... there are 3 diferent forces 1) force which causes tense of springs F=F_0cos(\omega t) 2) force of gravity (I susspect we can pass over it because for small deflection of bars is really little... 3) Restoring force of spring F=-kx What shall I do next ?

2 metal, thin, bars (length=l, mass=m) are hunging on same height (distance between bars-d) Lower end of bars are conected by metal spring (mass=0, k-spring constant, d-length) My problem is how to calculate a normal mode.

Ok. I know why the bars are oscillating, but my main problem is how. The frequency of force is 2xf, isn't it ? and now... there is problem with resonance... I must calculate a resonance frequency of coils or bars ? The mas of cails =0 so i suppose that a normal mode of an oscillating -->0.

thanks. Now i know... by the way... sorry for my not-recherche language. English is not my native language (I'm 17 from Poland-3 h eng for a week ;/ 37 people in my class ;/ as like Cambodia... ), so please be tolerate :)

I know that KE+Pe>0. And I know that escaping mass isn't locked in a circular orbit around the earth, but it's still got a kinetic energy from Earth rotation, so i don't know, is Kinetic energy a sum of kinetic energy of Earth rotation and energy which must be inserted to this object?

hello... I've got some small problem with Escape velocity. So... is it dependent on geographic coordinate ? I suppose "Yes!"... but is it true? Using conservation of energy, I calculate this velocity on equator this way: \frac{mv^2}{2}= \frac{GMm}{R} - \frac{m(2 \pi R)^2}{T^2*R } Am I right ?

Bob, I will be grateful if You could say something more... My main problem is How the force is conected with frequency.

so You mean that there will be a force between each of roll ? First i thing that the main force will be come from the bars... You know...F~I^2/d * l... Could You say something more ? But still I don't know how to conect a force and frequency... maybe f will be conected with period of...

Hi, It's my first poste here. 2 metal, thin, bars (length=l, mass=m) are hung on same height (distance between bars-d) Lower end of bars are conected by metal spring (mass=0, k-spring constant, d-length) Upper end of bars are connected with alternating current source (f-frequency). For...