Explain how the length of the day increases by 4minutes .
Answers
The length of a day increased by 4 minutes this is because of atmospheric refraction
When a Ray of light passes through the atmosphere it has different layer of densities and refractive index , then atmospheric refraction of light takes place
the actual Sunrise takes place when the sun is just above the horizon.
When the sun was just below the horizon, the light rays comes from sun enters to the earth's atmosphere and undergoes atmospheric refraction from rarer medium to a denser medium
So they bent towards the normal at its refraction
Due to continuous refraction of light at each different layer of atmosphere it follows a curved path and reaches the eye of observer little later.
As a result we see the sun 2 minutes before it Rises above the horizon .and 2 minutes after sunset.
so the time delay for observer from sunrise to sunset is totally 4 minutes
