Question

Forces a and B units act along the line X = 0 and Y = 0 on XY plane, what will be the equation of the line of action of the resultant?

Answer 1

hey mate
here's the solution

Answer 2

Given,

Force vector a is  along  the  X = 0, it means  vector  a is along  y axis.

Force vector b is  along  the  Y = 0, it means  vector  b is along  x axis.

Now, On completing  parallelogram(Rectangle in this  case), one  of the  diagonal will be  resultant  of  force.

Let  the resultant be  R,which makes  Ф angle  from  vector b,

Gradient of  line R,

m = tanФ

m = a/b

The line R  passes through point (0,0),

Hence, equation of  line R,

y-0 = m(x-0)

y = mx

y =a/b(x)

by = ax  

by - ax = 0 or , ax - by = 0

This is required equation.