Hey guys, I am stuck on this question. Can anyone give me some hints? I know the sum of the x and y components have to equal zero but I don't know how to find "the minimum". Here is the problem
Thanks!
Even just by looking at the diagram, the minimum F3 should be such thast F3 does not contribute to the F1. Meaning, F3 should have no horizontal component that would be pulled by F1.
So minimum F3 has zero horizontal component,
(F3)cos(alpha) = 0 -----(i)
For Eq.(i) to be true, if F3 is not zero, the cos(alpha) should be zero, so,
cos(alpha) = 0
alpha = arccos(0) = 90 degrees, for minimum F3 ---------answer.
And, minimum F3 = 137sin(30deg) = 68.5 newtons ------answer.