A runner runs 10 m from the origin toward the WEST to point A. He then runs from point A 20 m more toward the EAST to point B. He then runs from point B 30 m more toward the WEST to point C. The runner's total displacement from the origin to point C is
A) 60 m toward the WEST.
B) 50 m toward the WEST.
C) 20 m toward the WEST.
D) 10 m toward the WEST.
E) 0 m.

Question

Quizplus · Accepted Answer

To find the total displacement, we need to find the net distance and direction from the origin to point C. Since the runner moved towards the WEST by 10 m and towards the EAST by 20 m before moving back towards the WEST by 30 m, the net displacement is simply the sum of these distances in the direction of the final displacement. 
10 m WEST - 20 m EAST + 30 m WEST = 20 m WEST 
Therefore, the runner's total displacement from the origin to point C is 20 m toward the WEST. Answer choice C) is correct.

A Runner Runs 10 M from the Origin Toward the WEST