question_answer

A room (cubical) is made of mirrors. An insect is moving along the diagonal on the floor such that the velocity of image of insect on two adjacent wall mirrors is 10 cms?1. The velocity of image of insect in ceiling mirror is

A)            10 cms?1                                 

B)            20 cms?1

C)            \[\frac{10}{\sqrt{2}}\] cms?1 

D)            \[10\sqrt{2}\] cms?1

Correct Answer: D

Solution :

                   \[\nu \ \cos 45{}^\circ =10\] \[\nu =10\sqrt{2}\] cms?1 In the ceiling mirror the original velocity will be seen.