Recent content by NotACrook

So, treat the mass as just having linear velocity, the chain as the rotational, and the spring's potential? 0.5*mmass*vmass2+0.5*Ichain*ω+0.5*k*lextension2 0.5*0.5*122+0.5*0.6852*0.12*17.3^2+0.5*2500ish*0.045

Yeah, that is 2 - that typo only stayed as M, instead of 1/M, for that line, it went back to being a (1/0.5=2) the line below.

My logic was that the spring acting on itself was purely internal on that object so that the mass of the spring would only affect the whole system in that its mass would affect the centre of mass of the system. Where else does mspring come into play here?

Homework Statement A spring has mass Ms=120g and, if unstreched, length l=65cm. A boy attaches a point mass m=500g to one end of the spring. He holds the spring at the other end and spins it horizontally around his head, such that the point mass moves with speed v=12ms-1 and the spring is...

On a related note, just to make sure I have the concept: Each part of the 'string' would have a different wavelength due to the differing velocities v=SQRT(mg/Aρ), with ρ being different for each, right? Only the frequency would necessarily be constant?

I'd have thought that, so long as you calculate MoI around the edge and not halfway through, the distribution of mass would be fairly irrelevant so long as it is symmetrical? Hm, probably just a conceptual difficulty on my end. From the context, standing upright can be assumed. I'll work...

From what I can find, 1/2MR2 (noting the 1/2) is the equation for moment of inertia of a solid cylinder - since I already have the mass and its symmetrical with its density, won't that work? Wouldn't that end up with the same answer for VCM except using a different equation (V=U+at or...

Ok, taking M=1.1, I=0.5MR2 as correct, would I be correct in stating these equations for the later parts of the question (plugging in numbers of course): VCM: a=F/M V2=U2+2aS=0+2SF/M VCM=SQRT(2SF/M) Angular Velocity about CM: ω=VCM/R Kinetic Energy and Work Done: K=0.5MVCM2 +...

Yeah, went afk for dinner and worked on it a bit before checking back here, sorry. So, would I be correct in having that... dV = hπ(r+dr)^2-hπr^2=hπ(2rdr+dr^2) I seem to remember things like dr^2 can be discounted as being pretty much non-existant? M = ∫ρ dV = 2πh∫ρr dr = 2πh∫1600r-18000r2...

I'm.. honestly not sure how to do that. Could you give me the first step, possibly?

kg/m^3 for density, sorry. So, V=πr2h -> dV/dr=2πrh -> dV=2πrh dr 2πh∫∫∫Vρ(r,Φ,z)*r dr Well... Setting around the center of the cylinder, boundaries for Φ would be 0 and h, r and z both R to -R. Would that be correct? 40πh∫R-R ∫R-R ∫h0 80r-9r2 dΦ dr dz ?

Homework Statement Solid cylinder: H=0.14m, R=0.05m. Mass density ∂=900-(900r/0.05), where r is distance from axis of the cylinder. A string of negligible mass and length 0.85m is wound around the cylinder, which is set spinning by a horizontal pull on the string with F=2.5N. The cylinder...