Get the answers you need from a community of experts on IDNLearn.com. Get prompt and accurate answers to your questions from our community of experts who are always ready to help.
Sagot :
The focal length of the lens is 40cm.
What is the focal length?
The distance between the center of a lens or curved mirror and its focus.
A plane convex lens is made of glass ( n = 1. 5) with one flat surface and the other having a radius of 20 cm.
The focal length of the lens is given by the following formula;
[tex]\rm \dfrac{1}{f}=(n-1) \left ( \dfrac{1}{r_1}-\dfrac{1}{r_2} \right)\\\\Where; \ r_1 =\infty , \ r_2=20, \ and \ n = 1.5[/tex]
Substitute all the values in the formula;
[tex]\rm \dfrac{1}{f}=(n-1) \left ( \dfrac{1}{r_1}-\dfrac{1}{r_2} \right)\\\\\rm \dfrac{1}{f}=(1.5-1) \left ( \dfrac{1}{\infty}-\dfrac{1}{20} \right)\\\\ \rm \dfrac{1}{f}=(0.5) \left ( 0-\dfrac{1}{20} \right)\\\\ \dfrac{1}{f} = \dfrac{-0.5}{20}\\\\\dfrac{1}{f}=-0.025\\\\f = \dfrac{-1}{0.025}\\\\f=-40[/tex]
Hence, the focal length of the lens is 40cm.
Learn more about focal length here;
https://brainly.com/question/17205926
#SPJ4
Thank you for using this platform to share and learn. Keep asking and answering. We appreciate every contribution you make. IDNLearn.com has the solutions to your questions. Thanks for stopping by, and see you next time for more reliable information.
