question_answer

A hall has the dimensions \[10\,m\times 12\,m\times 14\,m.\]A fly starting at one corner ends up at a diametrically opposite corner. What is the magnitude of its displacement

A)             17 m                                         

B)             26 m                                         

C)             36 m                                         

D)             20 m

Correct Answer: D

Solution :

                Diagonal of the hall = \[\sqrt{{{l}^{2}}+{{b}^{2}}+{{h}^{2}}}\]                    \[=\sqrt{{{10}^{2}}+{{12}^{2}}+{{14}^{2}}}\]                    \[=\sqrt{100+144+196}\]             \[=\sqrt{400}=20m\]