A person who can produce sharp images on their retina only of objects that lie from 80 cm to 240 cm from the eyes needs bifocal lenses. Assume that the bifocal lenses are worn 2 cm from the eye. a) Determine the desired optical power of the lens enabling them to see far objects. Is this lens concave or convex?

with the invention of the automobile, the woman of the house could drive to the store and get groceries. women were also free to socialize more. during world war ii women were allowed to work in factories to the war effort and could drive to work or ride mass transit buses to their jobs.

blue light is scattered in different directions by the tiny molecules of air. blue is scattered more than other colours because it has a shorter distance to travel which results in smaller waves. this is why we see a blue sky most of the time.