1. The problem statement, all variables and given/known data A needle of length 5.0cm placed at the bottom of a beaker and a converging lens of focal length 20.0cm is held 30.0cm from the needle.The needle is illuminated with a lamp from the bottom.An image of the needle is formed on a screen.The beaker is now filled with water(refractive index=4/3)to a depth of 20cm.What change can be observed in the image? If the screen is moved to get a new sharp image,what will the image distance and object be in this new position?? i squeezed my brain so hard..still don hv any idea at all..becoz theres a space (air)between the lens and the water.When i am using the lens maker's formula,im confusing whether i should assume there r three lens -water,converging lens and water or two or one.. can somebody give some hints about how to solve it??