Question

The ball is initially at 2ȋ + 0ĵ + 3k̂ then it moved to 4ȋ + 0ĵ + 5k̂ , its total displacement is 6ȋ + 0ĵ + 8k̂ .

Answer 1

If the body is initially at 2ȋ + 0ĵ + 3k̂ and then it moved to 4ȋ + 0ĵ + 5k̂, the total displacement is

$$d=\sqrt{(r_{x2}-r_{x1})^2+(r_{y2}-r_{y1})^2+(r_{z2}-r_{z1})^2}=\\ =\sqrt{(4-2)^2+(0-0)^2+(5-3)^2}=2.83.$$