# Search results

1. ### Physics exam

In which nation do you live?
2. ### The pen revolves

Hi, Suppose that I am holding a pen in my hand and then i move my hand in such a way that the pen starts revolving around my index finger. It rotates in such a way that it seems that my finger is the center of the circular path(the path, through which the pen is revovling)...
3. ### Property of water

Hi I know what surface tension is but is this the only reason for it
4. ### Property of water

Hi When we fill a tumbler( of stainless steel) with water and then invert it ie empty it . The tumbler gets empty except a few drops of water. even if you keep the tumbler inverted for hours the water droplets do not fall down they remain stuck to the walls of the tumbler. I hope you...
5. ### What happens when a ray of light hits the boundary of the universe?

Hi Please forgive me if i am wrong but i think this equation tells us that greater the displacement of an object in space coordinates the lesser its displacement in time coordinates eg: If an object moves at a velocity close to light than time will move slowly for that object.
6. ### What happens when a ray of light hits the boundary of the universe?

When you talk about spacetime expansion, can you describe it more clearly:smile:
7. ### What is the Theory of Elasticity?

Hi chris I am from India and i dont boast that i have understood everything but yes many of the parts you explained were very lucid and easy to understand.
8. ### What happens when a ray of light hits the boundary of the universe?

Hi you are wrong for nothing exceeds the speed of light. You might be saying the above for the only reason that you might have a read an article saying that some experiments of nasa show that universe has expanded on all the sides by a great rate and they also think that the expansion of the...
9. ### Polarization of light

With you I would like to know first of alll what is right handed circularly polarized light and left handed circularly polarized light ??
10. ### What happens when a ray of light hits the boundary of the universe?

Hi As hubble explained that when a ballon having dots is blown than the distance between the dots increase and it increases more for those dots which are relatively far from each other.Now the universe has no boundary it is not that you will come to an edge and than you will fall off. Also...
11. ### Photoelectric Effect and metals

A short but clear explanation Hi The photons can only eject electrons when the frequency is greater than the work function. we know that the energy of the photon would be equal to hf. For eg if hf=phi than f is known as the threshold frequency here phi means the workfunction,now if hf>phi...
12. ### Movement of a shuttlecock

Thank you all for the replies:smile:
13. ### Movement of a shuttlecock

Hi Thankyou but then suppose that we have a single player and he just starts hitting the shuttle cock vertically in this case the shuttle cock travels vertical distance and then at the highest point it changes it behaves strangely ie in the beggining the cock faces us and and then it does...
14. ### What is the Theory of Elasticity?

Chris If i was from the awards commission than i would have surely giveen you the physics guru award for 2007. A great post . I have just completed my 10th grade but still i can understand it cool:rolleyes:
15. ### Movement of a shuttlecock

Quite a funny question Now when we hit a shuttle cock by racket or any other means, the shuttle cock moves in the direction of the force but halfway the position of the shuttlecock changes ie in the beggning the cock faces us and then at halfway the cock starts facing the opposite...
16. ### The double slit experiment

Hi, We all know that when we shoot electrons one by one on an apparatus having two slits then it forms a interference pattern. Means this implies that the electron passes through both the slits at the same time Now when we keep a detector near the slits to watch the...
17. ### The Millennium problems

Hi, Does anyone know about the Seven Millennium problems, if yes can any one explain to me the yang mills theory, navier stokes equation and the poincare conjucture in great detail:smile:
18. ### Why the Photon?

Welcome to the forums Now i dont know whether you are talking about topological manifold or a smooth manifold. But see photon is an elementary particle now the definition itself says that it is elementary. Now if we put your logic in physics than there would be...
19. ### Two slit experiment - quantum theory - problem

Welcome Hi i think that you must specify that whether there is a detector or not at any of the slits and whether the other slit is open or not.Other wise refer volume three of feynman lectures
20. ### Volume of Frozen water

Sorry But your friend is correct.the ice cube floats ie a bit of it is outside water. Now definetly the volume increases of the whole system but the amount by which the volume increases is exactly equal to the volume of ice outside water. now try to push the icecube in the water and...
21. ### Sun forms different geodesic

Thanks pete.If i am not wrong than In general relativity, gravity is not a force but is instead a curved spacetime geometry where the source of curvature is the stress-energy tensor.Now than does it mean that if planets are swapped, as caesium said,for eg if jupiter comes on earths place and...
22. ### Sun forms different geodesic

Hi pervect I know that true geodesic motion is ideolised for test particles.But many a times we can consider it for real mass.I accept that due to this some discrepencies arise likethe real mass affects the background geometry.But here i would just like to know as why different planets...
23. ### Sun forms different geodesic

I mean to say that.Earth moves on the geodesic formed by the sun's gravity.So along with earth we also have different planets revolving the sun.So does it means that the sun forms different geodesics for different planets.because all the planets are not in a single orbit they are in different...
24. ### Sun forms different geodesic

Hi, Earth follws a straight path in 4-d space time.ok.now the earth moves over the geodesic formed by the sun's gravity.now we also have other 7 planets.So does it mean that the sun forms different geodesic for differnt planets. if my question does make some logic than please explain me.

Hii simple.The water absorbs the heat and so the plastic doesnot reach its ignition temperature.So it doesnot melt.Once the water gets emptied the plastic starts burnin/melting
26. ### Definition of candela

Hi I cannot Understand properly the correct definition of candela.Can you please explain me.I know the definition by heart but i donot understand it properly
27. ### An excellent problem

Now i would like to know that how it happens it is against common sense.
28. ### An excellent problem

Hi pls read this its worth it.(assujme earth as a complete sphere) suppose i stand in india(place where equator passes) right now and now i begin my journey with a rope thousnands of kilometers long i follow the journey exactly on equator and return to the same place in india.means...
29. ### Niels bohr model

Hi, we know that we can find the radius and energy of the orbits of hydrogen.now why is it so that we cannot apply the same formulas for other elements by using the equations given by bohr.if there are complications what are they?
30. ### What make the electrons to move in conductor with current?

hi Hootenanny has explained very well.If you want a simpler explanation it follows To create a flow of any substance you have to develop a didfference between its two ends.whether it is a tube full of water or a conductor.when a potential difference develops at the two ends of a...