Q. A particle has initial velocity $(2\widehat{i} + 3\widehat{j})$ and acceleration $(0.3\widehat{i} + 0.2\widehat{j})$. The magnitude of velocity after 10 seconds will be
A) $9\sqrt{2}$ units
B) $5\sqrt{2}$ units
C) $5$ units
D) $9$ units
Explanation
(b) $\overrightarrow{v} = \overrightarrow{u} + \overrightarrow{a}t$
$v = \left( 2\widehat{i} + 3\widehat{j} \right) + (0.3\widehat{i} + 0.2\widehat{j}) \times 10$
$= 5\widehat{i} + 5\widehat{j}$
$\left| \overrightarrow{v} \right| = 5\sqrt{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.