Question

Ali walks 120 meter east, 150 meter south 40 meter east find the distance and displacement?

Answer 1

The distance

$$d=d_1+d_2+d_3=120+150+40=310\:\rm m.$$

The displacement

$${\bf s}={\bf s_1}+{\bf s_2}+{\bf s_3}$$ $$=120{\bf i}+(-150){\bf j}+40{\bf i}=160{\bf i}-150{\bf j}.$$

The absolute value of displacement

$$s=\sqrt{160^2+(-150)^2}=219\:\rm m.$$