Recent content by jimmy42

Yes thanks uart, I see how it's all working now.

Thanks uart, that helps a lot. I was thinking along those lines but couldn't make it fit. What about that {x^2} How does that become? {a^2} Thanks.

I have the vector: {\bf{u}}(x,y) = \frac{{x{\bf{i}} + y{\bf{j}}}}{{{x^2} + {y^2}}} Where: x = a\cos t y = a\sin t I know I need to use the equation \int\limits_0^{2\pi } {{\bf{u}} \cdot d{\bf{r}}} And the answer is \int\limits_0^{2\pi } {} ((a\cos t/{a^2})( - a\sin t) +...

Sorry, not sure if I follow. That equation I posted says that it is dependent on the angular frequency too, doesn't it?

But I guess that this equation links amplitude and the frequency? \begin{array}{l} A = \frac{P}{{\sqrt {{{(k - m{\Omega ^2})}^2} + {r^2}{\Omega ^2}} }}\\ \\ k = stiffness\\ m = mass\\ \Omega = frequency\\ r = damper\\ P = force \end{array} So, an increase in the angular...

Does changing the angular frequency change the amplitude of a forced oscillation? If so, I don't understand how that can be. I guess that the angular frequency is based only on the springs and dampers? So assuming those are the same then the angular frequency will always be the same? Are...

I have worked out that this is a strongly dampered equation, so I expect the amplitude to die down quickly. So, without frequency, this cannot be done? The question I have is to get the amplitude in order to solve the frequency between certain amplitudes. That last part can be done on the...

Hello, I have worked out some force diagrams for forced oscillations and ended up with the solution as : mx_double_dot+rx_dot+kx=Pcos(Ωt) I am now asked to work out the amplitude. I know all of the variables except frequency(Ω). What equations can I use to find that? Thanks.

Hello, If I have a vector A and then I do the dot product on itself so A°A. Then can I use that to find the maximum distance from the origin? If I take the derivative of the dot product then can I know at what time the maximum distance was travelled? I have done this but it is wrong...

I have the following simultaneous equations. However I am unsure how to handle that 2xy. Can someone give a pointer to any known methods? x= 3x^2+2xy y=x^2+3y+8

Hello, I have three differential equations, for these I have found the eigenvalues and eigenvectors. After that I made a vector general solution for the system of equations. From this vector, how can I predict the long term behaviour of the system? -Thanks.

Hello, I am having some problem with some algebra: 1 -x(t)= −Bω2 cos(ωt) −Cω2 sin(ωt) 2 - x(t)=−ω2 x(t) Can someone explain how we went from 1 to 2? Thanks.

OK, I think that just got me the equation for the acceleration of a resisted projectile r(t)= -g - (c*D^2*v/m) So, differentiating this twice should give the acceleration componet? I know the answer I should get and it does not match. Any help?

Homework Statement A ball travels vertically upward with quadratic air resistance, find the acceleration component. Homework Equations So, I have x pointing vertically downward and C=0.20 D = Diameter V=velocity W= -mgi R = -C^2D^2V^2 F=ma ma= -mg-C^2D^2V^2 The...

Yes thanks, i didn't think to convert it.