Q. A body is at rest at $x = 0.$ At $t = 0,$ it starts moving in the positive $x -$direction with a constant acceleration. At the same instant another body passes through $x = 0$ moving in the positive $x -$direction with a constant speed. The position of the first body is given by $x_{1}(t)$ after time $t$ and that of the second body by $x_{2}(t)$ after the same time interval. Which of the following graphs correctly describes $\left( x_{1} - x_{2} \right)$ as a function of time $t?$
A) [image:3_image73.emf]
B) [image:3_image74.emf]
C) [image:3_image75.emf]
D) [image:3_image76.emf]
Explanation
(b) There, $x_{2} = vt\ and\ x_{1} = \frac{at^{2}}{2}$
$x_{1} - x_{2} = - \left( vt - \frac{at^{2}}{2} \right)$
So, the graph would be like.
[image:3_image74.emf]
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.