Q. A body starts from rest from the origin with an acceleration of $6\ m/s^{2}$ along the $x$-axis and $8\ m/s^{2}$ along the $y$-axis. Its distance from the origin after 4 seconds will be
A) $56\ m$
B) $64\ m$
C) $80\ m$
D) $128\ m$
Explanation
(c) $S_{x} = u_{x}t + \frac{1}{2}a_{x}t^{2} \Rightarrow S_{x} = \frac{1}{2} \times 6 \times 16 = 48\ m$
$S_{y} = u_{y}t + \frac{1}{2}a_{y}t^{2} \Rightarrow S_{y} = \frac{1}{2} \times 8 \times 16 = 64\ m$
$S = \sqrt{S_{x}^{2} + S_{y}^{2}} = 80\ m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.