Question

An open merry go round rotates at an angular velocity `omega`.A person stands in it at a distance `r` from the rotational axis.It is raining and the rain drops falls vertically at a velocity `v_(0)`.How should the person hold an umbrella to prorect himself from the rain in the best way.Angle made by umbrealla with the vertical is
A. `cot alpha=v_(0)/(romega)`
B. `tan alpha=v_(0)/(romega)`
C. `cot alpha=(romega)/v_(0)`
D. `tan alpha=v_(0)/(romega)`

Answer 1

Correct Answer - A
Let th velocity of the drops above the person `rel.` to the merry go round be at angle `alpha` to the vertical. This angle can be determined from the velocity triangle `v_(0)=v_(rel)+v_(m.g.r)`,
`v_(rel)=v_(0)-v_(m.g.r)=(romega),cot alpha=v_(0)/(romega)`.