Two lenses, with f1 = +20.0 cnr and f2 = +30.0 cm, are

Chapter 27, Problem 47P

(choose chapter or problem)

Two lenses, with \(f_{1}=+20.0 \mathrm{~cm} \text { and } f_{2}=+30.0 \mathrm{~cm}\), are placed on the  axis, as shown in Figure  An object is fixed \(50.0 \mathrm{~cm}\) to the left of lens 1 , and lens 2 is a variable distance to the right of lens 1. Find the lateral magnification and location of the final image relative to lens 2 for the following cases:

     

(a) \(x=115 \mathrm{~cm}\);

b) \(x=30.0 \mathrm{~cm}\);

(c)  \(x=0\)

(d) Show that your result for part (c) agrees with the relation for the effective focal length of two lenses in contact, \(1 / f_{\text {eff }}=1 / f_{1}+1 / f_{2}\)

Equation Transcription:

         

 

     

   

     

Text Transcription:

f1=+20.0 cm and f2=+30.0 cm        

50.0 cm  

x=115 cm      

x=30.0 cm    

x=0    

1/feff =1/f1 +1/f2