Question

A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial position. Her displacement-time graph is shown in figure. Plot a velocity-time graph for the same.

Answer 1

For the initial $50$ second, velocity is $2m/s$. After that, velocity drops of zero, as shown by vertical line in graph.

For the next $50$ second, velocity is taken in negative because displacement is becoming zero.