# Recent content by silentwf

1. ### Is the system linear if there is an independant gravity term

So the system is non-linear? It's kind of strange to think of it in this way, so I'm not really sure.
2. ### Is the system linear if there is an independant gravity term

Okay, um then I should make it something like this: if my system is equation is something like: f - mg - u = 0 where f is the input and u is a disturbance (both are functions of time). having a scalar multiple of my force would not increase the system's response in a linear way. does this mean...
3. ### Is the system linear if there is an independant gravity term

Um, could you explain further by which variable you mean? I think I have the misconception that if there are any terms in the equation of motion not associated to input or output, the system is nonlinear, since the equation itself, when input or output is multiplied by a constant, does not...
4. ### Is the system linear if there is an independant gravity term

Like the topic,if in my system derivation, there is an independent gravitational force independent of the state variable, is my system linear? I believe it is not but my instructor is telling is it is. I'm thinking that if there is is an extra gravitational term,the output of the system does not...
5. ### Equation of Motion of a Inverse Pendulum on a Cart

Homework Statement The nonlinear, inherently unstable inverted pendulum is shown in Figure 1.15. The goal is to maintain the pendulum angle θ(t) = 0 by using a feedback controller with a sensor (encoder or poten- tiometer) for θ(t) and an actuator to produce an input force f (t). The...
6. ### Natural response of a RLC underdamped circuit?

Thanks for the replies, I asked a friend too, and he said it was just simple algebraic manipulation, so jim_hardy would be correct. I really did wish that the authors explain these things more clearly.
7. ### Natural response of a RLC underdamped circuit?

Not really sure whether this question belongs here or not (if it doesn't, help move?). So I was reading my electronic circuits textbook and am at the section of underdamped RLC unforced response, and the book mentions the natural response as v_{n} = e^{-\alpha\cdot t}(A_{1}\cdot...
8. ### Fluid Mechanics equations in Cartesian and Cylindrical coordinates?

OH! ok, I was wondering how to do it for a while. Sorry for the late response! and thanks guys!!
9. ### Fluid Mechanics equations in Cartesian and Cylindrical coordinates?

Homework Statement Not really a homework question, but more of a concept question which i'm unfamiliar with. So as we know, equations can be in any coordinate, but how do you convert them from one to another? For example, a few equations from fluid mechanics. the first equation is the vector...
10. ### The world revolves around a person

So basically, you can only say things move in relative to another only when they're not accelerating? or is it only when they dont have any angular rotation about a common axis?
11. ### 2nd order System steady state error

Homework Statement The system's closed loop transfer function is given below, find K and \alpha such that the input R(s) = 1/s^2 has no steady state error. (Hint: the system is not a unit feedback system) http://img829.imageshack.us/img829/9899/problempr.png [Broken] Homework Equations...
12. ### The world revolves around a person

This isn't the phrase egotistic or anything, but rather a random conversation i came up with my friends. We all know that people (and things) revolve around the world, but could one say that the world revolves around a person/thing? For example, if a car crashed into a wall, one could picture it...
13. ### Transient response of a system (control)

I agree. Thanks for your help though, really saved me from wasting hours on this problem.
14. ### Transient response of a system (control)

Hey, Okay, that was something I missed. After reworking it, there's still something wrong with it: [PLAIN]http://img35.imageshack.us/img35/6645/solk.png [Broken] as you can see, although i have solved for the values for %OS and Tpeak in the 3rd and 4th line of the picture, the solutions do...
15. ### Transient response of a system (control)

Homework Statement Find T,K value such that the system's percent overshoot is .254 and peak time is 3 http://img560.imageshack.us/img560/6139/problemz.png [Broken] Homework Equations [PLAIN]http://img46.imageshack.us/img46/51/releq.png [Broken] The Attempt at a Solution...