Recent content by Jwink3101

Nevermind. I thought about it more and realized that while the wheels and the treadmill speed will increase, the thing that is interesting is the force on the air and the plane will move forward. My flaw was that if you have a stationary plane and turn on the treadmill, the wheels will turn but...

Treadmill and an airplane NOTE: Never mind the question! I anwered it myself. Anyway, if you want to read it: ********************************************************************* I search quickly, but if this has been posted, please direct me and delete this threads...Anyway: There was a...

Thanks everybody. I like the Op-Amp idea a lot more becuase I tend to prefer op-amps over transistors (for a variety of reasons the least of which is that they are slightly less fragile). Anyway, I am still trying to work out how to get it to split off the way I want to the negative input and...

Thanks for the tip. That is also what I figured I would have to do...more or less. I read the article on Current Mirrors but I was not entirly sure i understood it (or the analysis). I will work through it again later tonight. I will say from my preliminary analysis of it, it seems like...

My 1kohm estimate must be off becuase come to think of it, when we use a current source (DC) we get 100mA for WELL UNDER the 40V max. Also, for AC, the 100mA is an upper bound Without going into too much detail, we are passing current through a fluid (salt water sometimes, an acidic chemical...

The problem is, we could use an op-amp but I need an AC source that will be the same regardless of the load. If that is easily doable with an op-amp, please let me know. I can only think of how to do it for a constant voltage.

I do not have a definite range of restistance but at least one test put it at about 1kohm. I have not tested it with the other load. The frequencies are actually very low. The maximum frequency we will use is 0.1Hz but ususlaly closer to 0.05Hz. I have been trying to get it with a simple...

First of all, i do not know if this is the ideal forum. If not, mods, please move it. Second of all, I know the title is redudant but whatever. Anyway, I am doing some experimental work that requires us to be able to controll the current, but we want to have it be a sine wave. We had been...

For what it is worth, my proffessor in Math Methods of Physics class often said if a mathematician were looking at this he or she would slap me but in physics, it works so we use it. Also, I know there are a lot of strange exceptions and rules we learned in math for certain theorems (Stokes...

So, when measuring sound intensity in decibels using the standard for J_0, by what power does sound fall off? My intuition says it should be r^{-2} because it spreads radially outwards but then there is air pressure and stuff like that in there.

Just think about it this way. \Delta V=V_{final}-V_{initial} so, if the initial velocity is 5 m/s and it comes to a dead stop, \Delta V=-5m/s. Assuming no mass loss, \Delta \vec{P}=m\Delta \vec{V}=\vec{F}\cdot t When doing impulse or the acceleration, that is when the time matters.

I may be comeplete wrong but aren't decibels 20Log(gain)? Also, the argument of the log must be unitless. [S]=\frac{W}{m^2}=\frac{J}{m^2\cdot s}=\frac{N}{m\cdot s} =\frac{kg\cdot m}{s^2}\frac{1}{m\cdot s}=\frac{kg}{s^3}\neq 1 I would just look at your equation again.

With regular DC motors, shorting them is not the same as turning them off. DC motors act as generators and when they are shorted, it is pulling a larger load and acts like a brake. I do not know how much you will see it with cheap or small motors but it is there. For example, with Lego...

Sorry, one more thing. Note that in physics there is not universal notation for the spherical system. The poster above me called the angle from the Z-axis \theta while I called it \phi. It is different in every book. In Shey's Div, Grad, Curl and All That, it is one way while in Sandri Hassani's...

I realized I should have continued. In these problems, you generally do not want to have the parameters of the surface in your answer. This makes sense becuase the charge inside shouldn't depend on the radius of your arbitrary surface. Notice in the euqation i put in my above post, the R...