Question

A room has dimensions $3m\times 4m\times 5m$. A fly starting at one corner ends up at diagonally opposite corner.
(i) what is the magnitude of its displacement?
(ii) If the fly does not fly but walks, what is the length of the shortest path it can take.?

• A. $\sqrt{50}m,\sqrt{74}m$
• B. $\sqrt{52}m,\sqrt{74}m$
• C. $\sqrt{58}m,\sqrt{74}m$
• D. None of these

Answer 1

The correct option is A $\sqrt{50}m,\sqrt{74}m$

(i)Displacement $=AB=\sqrt{5^2+3^2+4^2}=\sqrt{50}m$

(ii)$d^2=(l+b{)}^2+h^2=49+25=\sqrt{74}m$