Total distance covered 10m in 40sec
Total time taken= 2min 20sec= 140sec
1 round=10+10+10+0=40 m
Total round completed = 140/40=3.5 rounds
So If an object moves from A to D, the shortest path will be from A to C. So displacement is AC, that we will find by phythogoras theorem.
AC2= AB2 +BC2
AC2= (10)2 +(10)2
AC2= 100+100
AC2=200
AC = (200)1/2
AC= 10× (2) ½ =10x1.414=14.14m