Recent content by irishetalon00

Thank you PeroK. I think I got it. But to be sure, let me try to reiterate what you said in the context of my original question. ##\ddot{\mathbf{r}}## , which is the time derivative of ##\dot{\mathbf{r}}##, can also be thought of as being equal to ##\frac{d\dot{\mathbf{r}}}{dt}##, where...

I'm reviewing Meirovitch's "Methods of Analytical Dynamics," and I don't understand the commutation of the derivative from r to dr: $$ \mathbf{F} \cdot d\mathbf{r} = m \ddot{\mathbf{r}} \cdot d\mathbf{r} = m\mathbf{\dot{r}} \cdot d\mathbf{\dot{r}} $$

Homework Statement I need to find the discrete time equivalent of the following system: \begin{bmatrix} \ddot{x} \\ \dot{x} \\ \ddot{\theta} \\ \dot{\theta} \end{bmatrix} = \begin{bmatrix} 0 & 0 & 0 & 4.2042857 \\ 1 & 0 & 0 & 0 \\ 0 & 0 & 0 & 105.1071428 \\ 0 & 0 & 1 & 0 \end{bmatrix}...

Thank you for looking into this. How did you transform into the equations you have listed? No, I don't have any other constraints, unfortunately.

Homework Statement I have derived the differential equations of a system. They are like the following: a\ddot{\theta} - b\ddot{x} + c \theta = 0 \\ d\ddot{\theta} + e\ddot{x} = F(t) where a,b,c,d,e are constants. I'm having trouble putting it into state space form, since I have the highest...

I made a mental faux pas. The reason for the discrepancy is that the axes in MATLAB are not equal by default. Once I set the axes to be equal, my calculated angle matches the measured axis angle.

Homework Statement I am working in Matlab, and have a 3D plot that I made: x is parallel to axis labeled "lateral direction (m)" y is parallel to axis labeled "long. dir. (m)" z is normal to these (right hand coordinate sytem) The original view was looking parallel with +y. To get the...

Thank you for pointing me to relevant pages and explaining symbols.

Homework Statement (See attachment: if it doesn't work, see below for poorer formatting)[/B] Theorem 6.1 (Centered Formula of Order O(h2)). Assume that f ∈ C^3[a, b] and that x − h, x, x + h ∈ [a, b]. Then (3) f (x) ≈ f (x + h) − f (x − h) 2h . Furthermore, there exists a number c = c(x) ∈ [a...

Homework Statement Find where cos(x) = acos(x) Homework Equations Trig identities? The Attempt at a Solution I'm not sure how to proceed with this analytically. Cos(cos(x))=x? that doesn't seem to help...

Ok I liked that suggestion. Now I'm here: 0 = -149809 + x(-19806.4) + x^2(-99901.4) + x^3(49050) + x^4(62500) so now I have a quartic equation. Not sure how to proceed. I mean it should reduce to a quadratic somehow, right?

Homework Statement 0 = -250*(sqrt(x^2+1)-0.8)^2 + 98.1*x + 59.05 Homework EquationsThe Attempt at a Solution I can't figure out how to solve this equation! After expanding the squared term, I still end up with a sqrt(x^2+1) and I can't figure out how to perform a substitution or something to...

Homework Statement Need to find the moment of inertia of a cylinder, about its center of mass, about the three principle axes. Z axis is normal to the circular faces of the cylinder. mass = M, radius = R, height = h Homework Equations ∑miri2 The Attempt at a Solution The Izz for whatever...

I always thought that the onset of electrolytic capacitor leakage meant component failure, and therefore the remote wouldn't work at all. And secondly the "stuff" that comes out of caps is usually like a dark brown, right? I don't want to take the new one apart, as it never goes back together...

But *if* this "depositing" actually was the perpetrator, then why did it only collect around the bases of the capacitors? If the hard deposits were part of the original design (pre-spillage), then what did the spilling do to these deposits to cause them to short/conduct/whatever-they-were-doing?