question_answer

A man sitting in a bus travelling in a direction from west to east with a speed of 40 km/h observes that the rain-drops are falling vertically down. To the another man standing on ground the rain will appear                                  [HP PMT 1999]

A)                 To fall vertically down

B)                 To fall at an angle going from west to east

C)                 To fall at an angle going from east to west           

D)                 The information given is insufficient to decide the direction of rain.

Correct Answer: B

Solution :

                A man is sitting in a bus and travelling from west to east, and the rain drops are appears falling vertically down.                                 \[{{v}_{m}}=\] velocity of man                                 \[{{v}_{r}}=\] Actual velocity of rain which is falling at an angle \[\theta \] with vertical                                 \[{{v}_{rm}}=\] velocity of rain w.r.t. to moving man                                 If the another man observe the rain then he will find that actually rain falling with velocity \[{{v}_{r}}\] at an angle going from west to east.