Question

Force acting on a particle is $(2\overline{i}+3\overline{j})$ N. work done by this force is zero, when a particle is moved on the line 3y + kx = 5 Here value of k is

• A. 3
• B. 2
• C. 1
• D. 4

Answer 1

The correct option is B 2

Force is parallel to the line $y=\frac{3}{2}x+c$
and the given line can be written as $y=-\frac{k}{3}x+\frac{5}{3}$
as the work done is zero $\therefore$ force is perpendicular to the displacement
$\therefore \left(\frac{3}{2}\right)(-\frac{k}{3})=-1\Rightarrow k=2$