This question's from the book HIBBELER, R. Engineering Mechanics: Statics; chapter 4.
The curved rod lies in the x-y plane and has radius $3m$. If a force $F=80N$ acts at its end as shown, determine the moment of this force about point B.
The answer is $M_B = \{-37,6i+ 90,7j -155k\}N.m$
I can't make it to the right answer. I got $M_B=\{-37,6i+37,6j-75,1k\}N.m$
Please, I'll be grateful if someone help me. Thanks.