A man standing still finds rain pouring at an angle 30^(@) with vertical , when he starts walking forward at a speed of 4 kmph it appears to him that rainpours vertically down . When he runs at riple the speed, what is the angle at which rain appears to pour?

A man standing still finds rain pouring at an angle 30^(@) with vertic

1.	A man standing still finds rain pouring at an angle 30^(@) with vertical , when he starts walking forward at a speed of 4 kmph it appears to him that rainpours vertically down . When he runs at riple the speed, what is the angle at which rain appears to pour?
Answer» Solution :Case (i) : When the man is still `V_(R)`=actual (absolute ) velocity of rain. Case (ii) : When man WALK at 4kph, rain falls vertically means horizontal component of rain.s velocity=4 `:.V_(R)sin 30^(@)=4rArr V_(R)=8` Case (iii) : The man runs at triple the SPEED `V_(M)=12kph` We have superimposed `-V_(M)"to " V_(R)`to get the resultant. from figure , we see `tanphi=(O.B)/(OO)=(12-4)/sqrt(8^(2)-4^(2))=8/sqrt(48)=2/sqrt3:. phi=49` and raindrop makes an angle of `49.6^(@)` in opposite DIRECTION .