A"biconvex" lens is one in which both surfaces of the lens bulge outwards. suppose you had a biconvex lens with radii of curvature with magnitudes of |r1|=10cm and |r2|=15cm. the lens is made of glass with index of refraction nglass=1.5. we will employ the convention that r1 refers to the radius of curvature of the surface through which light will enter the lens, and r2 refers to the radius of curvature of the surface from which light will exit the lens. what is the focal length of the lens if it is immersed in water (nwater = 1.3)

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.