Question

Rain is falling vertically. A man running on the road keeps his umbrella tilted but a man standing on the street keeps his umbrella vertical to protect himself from the rain. But both of them keep their umbrella vertical to avoid the vertical sun-rays. Explain.

Answer 1

Hint :-The motion of both men with respect to the drops of rain will be found out with the help of relative motion analysis. here the position of the running man is changing with respect to the motion of the drops of the rain exactly above the man, thus these drops would miss meeting the man and the drops some distance ahead of the man would hit the umbrella of man, thus this relative motion is the main reason which forces man to hold the umbrella at some angle from its direction of motion.

Complete step by step solution
Here resultant of the velocity of a man running on the road will be at some angle so he has to hold his umbrella according to the resultant velocity but in the case of standing man on the street there is no relative velocity between man and rain so that he has to hold his umbrella vertically to protect himself

And in the case of light there is no relative motion between men and light because No particle can reach velocity of light. Velocity of light in vacuum, is a universal physical constant and independent of frame.

Note :- Statement comes from Maxwell's equation proofs the Velocity of light in vacuum, is a universal physical constant. Its exact value is equal to 299792458 m/s approximately 300000(3lakh) km/s.