Person A observes B moving in east direction with speed `10(m)/(s)`, B observes C moving in south direction with speed `20(m)/(s)`, C observes D moving in west direction with speed `30(m)/(s)` & D observes a tree moving with speed `40(m)/(s)` in north direction. Then the actual direction of motion of person `A` will be

Options

A. north-west
B. north-east
C. south-east
D. none of these

Answer

C

Explanation

All the velocities are marked in diagram where G represents ground
Adding we get
Then `vecV_(GD)+vecV_(DC)+vecV_(CB)+vecV_(GA)=-vecV_(AG)`
Hence veclocity of A is towards south east.