a) A student can easily identify the planets in a clear night sky among the twinkling stars and he
comes to a conclusion that planets won’t twinkle, Give justification to his conclusion.
b) Generally danger signal lights are red in colour. Why?
c) The Sun is visible to us about 2 minutes after the actual sunset. Why?
Answers
A ) I dnt know......
B) The primary reason why the color red is used for danger signals is that red light is scattered the least by air molecules. The effect of scattering is inversely related to the fourth power of the wavelength of a color. ... So red light is able to travel the longest distance through fog, rain, and the alike........
C) It is because of atmospheric refraction. When the Sun is slightly below the horizon, the light coming from it travels from less dense to more dense air and is refracted downwards. Thus, the Sun appears to be raised and can be seen 2 min before actual sunrise and 2 min after actual sunset.
Explanation:
a) because stars emit their own light whereas planets reflect light emitted by the stars
b) because red is the colour that is visible clearly
c) because everything in the universe need time to travel .
in same way light also travels very fast, faster than anything else in the universe at a speed of approximately 300000 kms per second but it takes time