Question
A man walking briskly in rain with speed v must slant his umbrella forward making an angle $\theta$ with the vertical. A student derives the following relation between $\theta$ and v: $\tan \theta = \text{v}$ and checks that the relation has a correct limit: as $\text{v}\rightarrow 0,\ \theta \rightarrow0,$ as expected. (We are assuming there is no strong wind and that the rain falls vertically for a stationary man). Do you think this relation can be correct? If not, guess the correct relation.
