radius of curvature = 2Focal length
The radius of curvature is given by(1)where is the curvature. At a given point on a curve, is the radius of the osculating circle. The symbol is sometimes used instead of to denote the radius of curvature (e.g., Lawrence 1972, p. 4).Let and be given parametrically by(2) (3)then(4)where and . Similarly, if the curve is written in the form , then the radius of curvature is given by
If you are given a chord length of a circle, unless you are given more information about the chord, you can not determine what the radius of the circle will be. This is because the chord length in a circle can vary from a length of (essentially) 0, up to a length of double the radius (the diameter). The best you can say about the radius if given the chord length, is that the length of the radius is at least as long has half half the chord length.
You also need to know the index of refraction. For glass, that is usually somewhere around 1.5. The Wikipedia article on "Lens (optics)" includes the "Lensmaker's equation"; usually you can use the "thin lens equation" (further down in the article) as a convenient approximation. Since for this question you don't know the radius of curvature, and the equation includes two radii of curvature (for the two surfaces), I suggest that you make one of the following simplifying assumptions: 1) Either assume that the lens has two surfaces of equal curvature (note: for the equation in the Wikipedia article, the signs would be opposite for both sides), 2) Or, assume that the lens has one flat side and one curved side.
(arc length / (radius * 2 * pi)) * 360 = angle
Looks to us like it's another circle, concentric with the first one, with radius of sqrt(5) = 2.236 . (rounded)
NO it cannot be. Because radius of curvature is given by the expression R = 2 f
In a plane mirror, the radius of curvature is infinitly long, so the focus will be at infinity. Another way to say it is that a plane mirror has no curvature, and as curvature becomes increasingly small, focal length becomes increasingly long. At a curvature of zero, focal length becomes infinite. Focal length(f) is given by f=R/2 where R is radius of curvature.. Once again, it's infinity! See answer to your question on radius of curvature. Plug infinity (radius of curvature) into your mirror equation to get the focal length, which will also be infinite. A flat mirror does not focus incoming parallel beams. That's because if you say its at infinity it means it does exist in a finite distance, that is instead of saying it does exist its taken at infinite distance for only theoretical importance and not for practical observance. Focal length is half of radius of curvature of the mirror. So bigger the circle gets the more its radius will be. So in the same way as the curvature of the sphere gets less and less its focal length increases, so when it becomes totally flat the focal length will become infinite so it means it has no existence but it has only theoretical importance. It same as taking the formation of image of an object at principal focus to be at infinite distance rather than saying it does not form ( that is both mean the same). hope my answer is satisfactory
The size (diameter) of a lens does not determine its focal length. The amount of curvature of the lens does. Citing a diameter for a lens doesn't help us find the focal length. Lenses are ground to specifications that allow short or long focal length. The more curved the lens, the shorter the focal length. You can see this if we specify a given curvature and then start to "flatten" the lens. The focal length will get longer and longer as the lens is flattened. When the lens is flat (has to curvature) the lense has an infinite focal length, just like a piece of flat glass.
The radius of curvature is given by(1)where is the curvature. At a given point on a curve, is the radius of the osculating circle. The symbol is sometimes used instead of to denote the radius of curvature (e.g., Lawrence 1972, p. 4).Let and be given parametrically by(2) (3)then(4)where and . Similarly, if the curve is written in the form , then the radius of curvature is given by
The radius of curvature of a circle, or an arc of a circle is the same as the radius of the circle.For a curve (other than a circle) the radius of curvature at a given point is obtained by finding a circular arc that best fits the curve around that point. The radius of that arc is the radius of curvature for the curve at that point.The radius of curvature for a straight line is infinite.
There is not enough information to answer the question.
If you are given a chord length of a circle, unless you are given more information about the chord, you can not determine what the radius of the circle will be. This is because the chord length in a circle can vary from a length of (essentially) 0, up to a length of double the radius (the diameter). The best you can say about the radius if given the chord length, is that the length of the radius is at least as long has half half the chord length.
There is no such expression. The normal to a surface, at a given point is the radius of curvature of the surface, at that point.
The focal ratio ( 'f' number ) is the ratio of focal length to diameter. For the numbers given in the question, assuming they're both in the same unit, this telescope is a 25/5 = f/5.
You also need to know the index of refraction. For glass, that is usually somewhere around 1.5. The Wikipedia article on "Lens (optics)" includes the "Lensmaker's equation"; usually you can use the "thin lens equation" (further down in the article) as a convenient approximation. Since for this question you don't know the radius of curvature, and the equation includes two radii of curvature (for the two surfaces), I suggest that you make one of the following simplifying assumptions: 1) Either assume that the lens has two surfaces of equal curvature (note: for the equation in the Wikipedia article, the signs would be opposite for both sides), 2) Or, assume that the lens has one flat side and one curved side.
The radius is a cord, is it not?
(arc length / (radius * 2 * pi)) * 360 = angle