Question

Force acting on a particle is [2i+3j]N ,Work done by this force is zero,when the particle is moved along the line 3y+kx=5,here the value of k is?

Answer 1

As workdone is zero, direction of force must be perpendicular ot direction of motion. Slope of the line = -kx/3 =m1 (say)
m2= direction of force = j/i=3/2
As they are perpendicular m1*m2= -1
=> k=2

Answer 2

Answer:

Explanation:

F=2i+3j

Tan = y /x =3/2

3y +kx= 5

y=-kx+5/3

y=MX+c

-kx+5/3=MX+5

M =-k/3

Mm=-1

3/2*-k/3=-1

k/2=1

K=2