Recent content by mathfan

Yes l' is a derivative. It is all I have in my assignment

In my exercise is: Assume forces: 1. Spring elasticity: F=-kΔl 2. Dissipation/damping: F=-cl' So I don't think it's the same.

No -cl' isn't constatnt, l(small L) is the length of the spring(dependent on the angle)

I'm supposed to this classically, but I'm not allowed to make a small-angle approximation. There is also dissipation F=-cl'. I can't even imagine how this system works. I worked out length of the spring (dependent on angle) using law of cosines, but i don't know if it's a good idea.

So, i have to find equation of motion for this system. We know length of the line (L) and L1(picture). Initially the angle between spring and line(L) is 90, so initial length of the spring is √(L1^2-L^2). What's more the the pendulum rotates around the main rod ( angular velocity ω). Yes my post...

Homework Statement I have to derive equation of motion for this system. I want to use a moment of force, but i have a problem with moment of force spring. Homework Equations The Attempt at a Solution What I've done is: M(Fg)=-mgLsinα M(N)=0 M(Fb)=mω^2 Lsinα*Lcosα mL^2*α''=ΣM M(Fs)=?