(adsbygoogle = window.adsbygoogle || []).push({}); physics contest-- question 3

a) Complete the drawing below to show where the image of the object formed by the lens is

b) Use the drawing you have cpmplected, prove that 1/s + 1/s' = 1/f/

Here s is the distance bewteen the object and the lens, s' is the distance between the image and the lens, and f is the distance bwteen either of the focal points F and the lens.

c) Prove that the image magnification is M = s'/s

Part a, c : no problem

How do you do part b ?

Here's my answer.

After completing part a, my measuring the picture i drew, I got

s=5.9 cm

s'=6.1 cm

f =3 cm

1/s + 1/s' = 0.333

1/f = 0.333

QED (At least I can amuse the markers )

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Physics contest- question 3

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**