please help. i know its true but why?True or false? the focal length of a converging lens in h20 is larger in abs value compared to its f in air?
It's true because by Snell's law (畏sin胃1 = 畏2sin胃2) there is a smaller refraction angle (difference between 胃1 and 胃2) when the values of index of refraction 畏 are more nearly equal. 畏 of air ~= 1 while 畏 of water ~= 1.33, closer to that of glass ~= 1.5 to 2. Think of what the f would be if the lens were 'immersed' in glass: infinite, right?
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