Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
Home  >>  JEEMAIN and AIPMT  >>  Physics  >>  Class11  >>  Motion in a Plane
0 votes

Rain is falling at the speed of 4 km/hr from west direction making an angle $30^{\circ}$ with vertical. At what speed should a man walk eastward, such that he has to hold his umbrella vertically to protect himself

\[(a)\;6.518 km/hr\quad (b)\;2 km/hr \quad (c)\;3.464 km/hr \quad (d)4.236 km/hr\]

Can you answer this question?

1 Answer

0 votes
Relative velocity of rain w.r.t. man must be vertical.
=> the resultant of $v_{\large rain}$ and $(-v_{\large man})$ must be vertical.
$\large\frac{v_{\Large m}}{v_{{\Large rain}}}=$$\sin 30^{\circ}$$=\large\frac{1}{2}$
Hence b is the correct answer.
answered Jun 27, 2013 by meena.p
edited May 23, 2014 by lmohan717

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App