Can a converging lens become a diverging lens in liquid?

[haha1234]

Homework Statement

(a)Can a converging lens be made to diverging if it is placed into a liquid?
(b)What if?What about a converging mirror?

Homework Equations

Homework Equations

The Attempt at a Solution

The Attempt at a Solution

(a)Let the focal length of the converging lens be f1,and the focal length of the lens be -f2.From the formula

,when the magnitude of f2 is larger than f1,the new focal length we get is smaller than 0,so converging lens can be made to be diverging.
Is it correct?
In (b),can we use the formula again?

THANKS!

 

[adjacent]

If you put an object closer than the focal length,it's light rays will be diverges,so you will see a virtual image.

 

[adjacent]

Try out my program,
https://dl.dropboxusercontent.com/u/260388836/index.html

 

[Dadface]

Your question is ambiguous haha. Did you mean to say "can a converging lens be made into a diverging lens if it is placed into a liquid?" If so you need to consider the refractive indices of the lens material and the liquid into which it's placed. If you wish to refer to an equation then use the equation that gives focal length in terms of the two refractive indices and the radii of the lens faces. Try googling.