Q. A body moves 6m north, 8m east and 10m vertically upwards, what is its resultant displacement from initial position?
A) $10\sqrt{2}m$
B) 10m
C) $\frac{10}{\sqrt{2}}m$
D) $10 \times 2\ m$
Explanation
(a) $\mathbf{r} = x\widehat{\mathbf{i}} + y\widehat{\mathbf{j}} + z\widehat{\mathbf{k}}$
$\therefore\mathbf{r} = \sqrt{x^{2} + y^{2} + z^{2}}$
$\mathbf{r} = \sqrt{6^{2} + 8^{2} + 10^{2}} = 10\sqrt{2}m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.