Have I Labeled 1/f=1/u+1/v Correctly?

  • Thread starter Thread starter gracy
  • Start date Start date
AI Thread Summary
The discussion focuses on the correct labeling of the thin lens formula, specifically the variables f, u, and v. It clarifies that f represents the focal length of the lens, while v denotes the distance from the lens to the image. Participants highlight common mistakes, such as not considering the focal point and measuring distances from the optical center. Recommendations are made to consult reliable physics textbooks for clearer understanding, as online resources may vary in quality. Overall, accurate comprehension of these concepts is essential for mastering lens optics.
gracy
Messages
2,486
Reaction score
83
Have I labeled correctly?
have i labeled it correctly.png
 
Physics news on Phys.org
This looks like it should be posted in the schoolwork forums, gracy. And are you familiar with the thin lens formula? That is basically what you are asking about. Check it out on wikipedia for more info.
 
gracy said:
Have I labeled correctly?
Almost. u and v are correct, but not f. f is the focal length of the lens, not the distance from lens to image. (That's what v is.) Look it up!
 
  • Like
Likes gracy
Doc Al said:
f is the focal length of the lens, not the distance from lens to image. (That's what v is.)
I got you point.I think the image below greatly explains all the three f,v,u.
diagram10.gif

I was doing following mistakes.
1-I was not considering focal point . If the light rays converge (as in a converging lens), then they will converge to a point. This point is known as the focal point of the converging lens. If the light rays diverge (as in a diverging lens), then the diverging rays can be traced backwards until they intersect at a point. This intersection point is known as the focal point of a diverging lens.
2-I was confused about focal length.Focal length is distance between optical center and focal point.
3-All the distance should be measured from optical center.So ,in the previously attached image i.e
65921-bd501138b1af5041ab392f82387e353b.jpg

u and v was not correct in the sense that the distance was not measured from optical center.I think that's what you meant by
Doc Al said:
Almost u and v are correct
 
Last edited:
@gracy
Do you have a good old fashioned School Physics Text Book? Many of the questions you have been asking (on this and other topics) are dealt with in books and you can usually rely on them to get things right.
It may depend upon which part of the world you are getting your Science education and I know there are some ridiculously elementary Science courses in some places. If your course is badly lacking, then you really should invest in a decent book. These days, the Internet can get any book to anybody, anywhere. It may be your best way forward.
 
  • Like
Likes Doc Al
I think it's easist first to watch a short vidio clip I find these videos very relaxing to watch .. I got to thinking is this being done in the most efficient way? The sand has to be suspended in the water to move it to the outlet ... The faster the water , the more turbulance and the sand stays suspended, so it seems to me the rule of thumb is the hose be aimed towards the outlet at all times .. Many times the workers hit the sand directly which will greatly reduce the water...
comparing a flat solar panel of area 2π r² and a hemisphere of the same area, the hemispherical solar panel would only occupy the area π r² of while the flat panel would occupy an entire 2π r² of land. wouldn't the hemispherical version have the same area of panel exposed to the sun, occupy less land space and can therefore increase the number of panels one land can have fitted? this would increase the power output proportionally as well. when I searched it up I wasn't satisfied with...
Back
Top