explain the following: a) a coin placed at the bottom of a vessel appears to be raised when water is poured in vessel b) a straight stick partly dipped in water obliquely, appears to be bent at surface of water. c) the sun is seen before the sunrise and after the sunset
Answers
Answer:
Because of refraction of light.
Explanation:
a) When the coin is under water then due to refraction of light, a virtual image of the coin is formed nearer to the water surface. And since the virtual image of coin which we see , is nearer to the water surface, so the coin appears to rise on adding water in the basin.
b) When a straight stick partly dipped in water and help obliquely to the surface, the apparent bending of the stick is due to the refraction of light when it passes from water into air. It is actually the light passing from water to air that is bent.
c)It is due to atmospheric refraction that we can see the sun for about 2 minutes even after the sun has set below horizon.( atmospheric refraction of light caused by the earth atmosphere, having air layers of varying optical densities is called atmospheric refraction).