# Search results

1. ### Op amp problem Vs = Vout

Hi! I solder the following circuit: http://en.wikipedia.org/wiki/File:Op-Amp_Non-Inverting_Amplifier.svg With an opamp of +-5V or 0-10V operation I use a 12V dc supply and give a Vin of 0.05V with resistors 10k and 1k. For all cases no matter what I supply I get Vout = Vsupply...
2. ### Finding the radius based on time and velocit

With regards to your approach: w*r = v Here you are confusing centripetal acceleration with angular acceleration. Although there is a force (and thus an acceleration) maintaining the centripetal motion there is no acceleration of the speed of this motion as the acceleration is always tangent (in...
3. ### Kinematics problem(already have the answer, but i need an someone to explain it to me

You can ignore the first part up until t1 = 5s as the distance between the two objects remain 60m. What happens then is x1 - x2 = 0 where x1 = s1_0 + v1_0*t and x2 = s2_0 + v2_0*t + 1/2*a2*t^2. (x_1 is not experiencing any acceleration so a1 would be 0) We also know that s1_0-s2_0 = 60. Also...
4. ### Fall Project!

Awesome project. I am afraid you will have to provide a bit more information if you expect any help. Mention any ideas you have considered. Tell us where the pitfall of these ideas are and provide more specific questions such as "I can design a 2d pendulum that activates a button after a...
5. ### Surface normal directions

Do you have a plane equation or do you only have the coordinates of a point? Please be more specific.
6. ### Focusing Light

Your assumption is correct but as Andy mentioned you need to be aware of aberrations unless the beam fills the entire lens (reason why you might want to have a beam expander/collimator using two lenses instead of one). 1) is correct 2) instead of having a beam radius of say a couple of...
7. ### Focusing Light

Placing the biconvex lens it's focal length away from the source will collimate the beam. If you're lucky enough the resulting beam will have a diameter close to whatever aperture you're trying to fill. Otherwise you will have to get a second lens to make a beam expander/collimator. Edit: I...
8. ### Microscope field of view & depth of field/focus (confocal microscopy)

Thanks Andy, I've read all of it though. I have yet to read about a comparison between depth of view and bleach depth. I find it very strange to read about FRAP without and with a confocal setup. The only way I could see the non confocal approach working would be with a very thin specimen...
9. ### Mechanics of solids question from my mid semester exam

The force from the water per m is: The integral of the pressure due to the water (from 0 to h)
10. ### Microscope field of view & depth of field/focus (confocal microscopy)

Hi I am trying to run a FRAP (fluorescence recovery after photo-bleaching) experiment but I am struggling a little bit. For those not exposed to the technique it involves, for example, bleaching a spot in a specimen that is fluorescing rendering that spot dark in contrast. I have two separate...
11. ### Problem in Car's Braking

3 ways to change the natural frequency or response. Mass, stiffness or introduce damping. As an engineer I would introduce damping but unfortunately I'm not a mechanic so I do not know what the correct automotive solution is :D
12. ### Presentation on Permeability

http://en.wikipedia.org/wiki/Permeability_(earth_sciences [Broken]) For some very interesting simulations check out lattice boltzmann equation (simulations)
13. ### Studying What is the reality of studying maths in the UK?

At top unis (and most respected institutions) in the UK they require A or A* in Maths and Further Maths A-levels. In some cases they even require the STEP paper which is very difficult. This is certainly not an easy requirement and similar to getting a 6-7 in IB Math HL (allthough that course is...
14. ### Thermal deflections

I would say it is not possible and I cannot see anything you've done wrong. I'd say it's logical that it would depend on the initial length due to 5mm being a fixed value. Imagine L0 being 1e-10m. An large deltaT would be required. With L0 being extremely large, the opposite would apply. Agree?
15. ### Rotation of flows

Sorry but did you write the question exactly as it was posed and with everything included? I'm a bit startled.
16. ### Thermodynamics question: Irreversible process

Unless it's a trick question or I have misunderstood something you have neglected the term irreversible. To be fair I've never heard of the term adiabat but I assume it means the exponential PV-line for an adiabatic reversible process. Only reason I do this is because I have an idea of what they...
17. ### Wave speed, tension, linear density

As you solve for tension without manipulating the equations the answer is naturally in N.
18. ### Thermal deflections

What happens if you divide the first equation with the second?
19. ### A push to an object in complete vaccum.

I am saying that if a player kicks a ball in real life then it looks like the ball is accelerating away from the player due to him decellerating his foot. It is actually moving at constant velocity (ignoring gravity and friction). If he kicks the ball in vaccum he would have no way of...
20. ### Thermodynamics question: Irreversible process

You're saying there's only one adiabat that goes from 1 to 2. Are you sure this is correct? Because you're saying there is one reversible adiabatic process while the question asks for an irreversible adiabatic process. How would these two processes differ? Think about this for a minute.
21. ### A push to an object in complete vaccum.

It is not accelerating. It is accelerating relative to the player's foot due to the decelleration of the player's foot.
22. ### Laser optical components/setup

Excellent, thank you.
23. ### A push to an object in complete vaccum.

Agreed except for the limitation of relativity?
24. ### Laser optical components/setup

Yes. Fluorescent particle tracking.
25. ### Laser optical components/setup

Oh, found that but forgot about it. Thanks :D
26. ### Laser optical components/setup

Hi I just started a PhD where I am going to use lasers to measure fluid flow among other things. I am looking for some helpful information about otpical components and techniques mainly relating to lasers. How to correctly design a setup, how to split beams, how to expand/contract beam...
27. ### Neglecting brownian diffusion

I am going to run an experiment where I have a laminar flow of water with a dye solvent. It is necessary that the velocity of the dye particles is mostly in the horisontal directions. Naturally particles will diffuse but my questions is how I can ascertain that this is kept below some...
28. ### Non-uniform bi-linear interpolation

I have a perfectly good understanding of tri-linear interpolation although my question might have seemed unclear. Here I was simply trying to find a solution for the bi-linear problem which I would the extrapolate to the tri-cubic one. In any case I found a solution to the problem and it is...
29. ### Non-uniform bi-linear interpolation

I have a non-uniform grid within which velocity data is known at each grid point. This velocity data is to be interpolated to allow for evaluation of velocity at an arbitrary point inside the grid. I am wondering about the correct approach to this problem. In actuality I want to evaluate the...
30. ### Visualising the effect of surface tension

Hello! I am using the Lattice Boltzmann method to simulate multiphase flow. The details are not important but the main drive behind multiple phases being simulated is interparticle forces. Now I am trying to visualise intuitively how such interparticle forces will cause a fluid to experience...