The discussion focuses on solving a concave lens problem using the equation for image formation through refraction at a single surface, specifically \(\frac{n_1}{p}+\frac{n_2}{q} =\frac{n_2-n_1}{R}\). Participants clarify that Snell's law, \(n_1 \sin \theta_1 = n_2 \sin \theta_2\), is relevant for understanding refraction but not directly for image formation in this context. Key points include the correct application of sign conventions for object distance (p) and image distance (q), as well as the correct interpretation of the radius of curvature (R). The final solution for q is determined to be negative, indicating the image is formed on the front side of the lens.
PREREQUISITESStudents studying optics, physics educators, and anyone seeking to understand the principles of image formation through concave lenses and refraction.
alphysicist said:Hi jcpwn2004,
The problem here is not a thin lens problem; it is finding an image produced by a refracting surface. What equation would you use for these problems?
jcpwn2004 said:ummm i really don't know lol, i thought refraction had to do with the n1sin01=n2sin02 equation...
alphysicist said:That equation (Snell's law) does describe the refraction of a light ray as it passes from one medium to the next.
However, in this problem we want to know how refraction at a single surface creates an image. You can use Snell's law to derive an expression that tells how an image is formed for light refracting from a surface. Your textbook probably does this for you and gives you the final result, which is something like:
<br /> \frac{n_1}{p}+\frac{n_2}{q} =\frac{n_2-n_1}{R}<br />
Many books use many different symbols for the quantities in the denominators, so look for a section titled something like "image formed by refraction" to find out how it's written in your book. (The section is commonly between the section on spherical mirrors and thin lenses.)
Once you find it, you'll need to interpret what the symbols mean, and then apply it to your problem. What do you get?