Precipitation from the sky to the earth can come in several forms. Four types are:
1) Rain
2) Snow
3) Sleet (think of a more liquidity slushy snow)
4) Hail (pretty much solid chunks of ice)
Explanation:
Formula which holds true for a leans with radii
and
and index refraction n is given as follows.
Since, the lens is immersed in liquid with index of refraction
. Therefore, focal length obeys the following.
and,
or,
= 32.4 cm
Using thin lens equation, we will find the focal length as follows.

Hence, image distance can be calculated as follows.


= 47.9 cm
Therefore, we can conclude that the focal length of the lens in water is 47.9 cm.
The size has gotten smaller, they last longer, easier to carry around, safer, etc
The magnetic particles are mixed with other substances to make it flexible.