Question

Plz can smone help me in this out.

Answer 1

It can be solved using the definitions :
average velocity = total displacement/total time

here, total displacement till 4 seconds = 10m

time till 4 seconds = 4 seconds (obviously)
therefore, average velocity for 1st 4 seconds = 10/4 = 2.5m/s

at the end of 10s , displacement from initial position (from graph itself) = -10m

he reaches starting point after 7s, 13s