PG-15

Ok warning cause there are hints fo some mature stuff here! If you don't understand, it's better you don't.

-Two thin lines of focal length 15 cm and 20 cm respectively are put in contact. Find the focal length of the combination and-

‘GAHH!!!
I HATE YOU WHOEVER YOU ARE FOR INVENTING PHYSICS!!! AND I HATE YOU ONEW
FOR MAKING ME TRAY ( Read more... )