Is the Calculation of Resultant Forces Correct?

[mm391]

Homework Statement

I am trying to find the resultant forces in the attached picture.

Homework Equations

The Attempt at a Solution

The resultant of a couple of forces = 0
F in x direction = 5cos(45)
F in y direction = -5sin(45) - 2

Therefore:
R = ((5√2)/2)i + ((-(5√2)/2)-2)j
R = √(3.53^2+(-5.53)^2) = 6.56kN

is this correct does the distance of the 2kN force come into play somewhere. If so where?

 

[tiny-tim]

hi mm391!

looks ok so far …

now you need to find the line along which it acts (of all the possible parallel lines)

 

[mm391]

Thanks Tiny Tim but I am still al ittle confused.

What do you mean "find the line along which it acts" ? What line. All I can see it that the 2kN force acts 6 meters from point P but I am not sure how to incorporate that into the question.

Thanks

 

[tiny-tim]

a force that is (say) 10 N north-east can be applied anywhere along a rigid body

if applied on the left side, it will turn it clockwise, if applied on the right side, it will turn it anti-clockwise

the point of application (or the line of application, through that point) matters, and when specifying the resultant of forces, you must also specify the line of application