The work done by the force F = 2i - 2j + 2k is displacing a particle from the point (3,4,5) to the point (1,2,3) is

Question

The work done by the force $\mathbf{F}=2 \mathbf{i}-2 \mathbf{j}+2 \mathbf{k}$ is displacing a particle from the point $(3,4,5)$ to the point $(1,2,3)$ is

(a) 2 units

(b) 3 units

(c) 4 units

(d) 5 units

Answer 1

Now,  $\mathbf{d}=(3-1) \mathbf{i}+(4-2) \mathbf{j}+(5-3) \mathbf{k}=2 \mathbf{i}+2 \mathbf{j}+2 \mathbf{k}$ 

$\therefore$ Work done $=\mathbf{F} \cdot \mathbf{d}=(2 \mathbf{i}-3 \mathbf{j}+2 \mathbf{k}) \cdot(2 \mathbf{i}+2 \mathbf{j}+2 \mathbf{k})$ $=2$ units

So, The correct option of this question will be (A).