A concave mirror and a convex lens are held separetly in water. What changes, if any, do you except in the focal length of either?

A concave mirror andaconvex lens are held in water. What changes if any, do you expect in their respective focal lengths as compared to their values in air.

What is the focal length of a plane mirror?

What is the focal length of a plane mirror ?

A concave mirror is held inside water.What would be the cahgne in the focal length of the mirror?

Find the power of a concave lens of focal length 2 meters?