Thank you for reporting, we will resolve it shortly
Q.
Which of the following curves represents the $v-t$ graph of an object falling on a metallic surface and bouncing back?
Motion in a Straight Line
Solution:
When an object falls down its acceleration is downwards and constantly $g$. Its velocity is downward. On bouncing its velocity is upward but acceleration is still downward and constantly $g . v-t$ graph should have same slope in both phases of motion, one half must be positive velocity and the other half must be negative velocity.