# Recent content by ponjavic

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.