Equivalent force-couple system (conceptual)

[jaredmt]

on a 3d graph i have 3 forces in different places pointing different directions. I am supposed to find the equivalent force-couple system about some point D. but 1 of the forces is aligned with point D and therefore creates no moment about D.

how would i do this? Do i just find the moment of all the forces about point D and then put the Resultant of the 3 forces on D?

 

[tiny-tim]

Hi jaredmt!

on a 3d graph i have 3 forces in different places pointing different directions. I am supposed to find the equivalent force-couple system about some point D. but 1 of the forces is aligned with point D and therefore creates no moment about D.

how would i do this? Do i just find the moment of all the forces about point D and then put the Resultant of the 3 forces on D?

Yup … add all the forces, and add all the moments …

if one of them is zero, that saves you time … so have a cup of tea!