1. The problem statement, all variables and given/known data A body is located at (-2m, 0, 4m). An force is applied at this body Fx=6N. Determine the torque. 3. The attempt at a solution First of all I apologize for my insane paint skills. Yes, I'm very talented, thank you. Ok, I thought I new how to calculate torque, but this question confused me greatly. Now here's the thing, there are two ways of calculating Torque (which are really the same thing, but still, two ways): One of those is using the right hand rule to determine the sign, getting the magnitude of R and using the magnitudes and sin of the angle between them to calculate Torque. The other is getting the vectors and doing vectorial product, using matrix determinant. Sometimes I do in both ways to sort of 'proof-read' my results, and in this case I'm finding conflicting results. Let's just get the pointless calculations out of the way: [itex]r = 4.47m \\ \theta = 63.43°[/itex] Ok, with all that said, let me show you what I did: 1) [itex]\tau = 4.47*6*sin(63.43°)*(-1) = -23.98N.m[/itex] Why the (-1)? Well, because of the right-hand rule (and I think the error lies here). The rule states that I should put my fingers along the r dirirection, and curl them towards the force F, therefore, by the drawing we can all see that it would be negative. 2) (calculating the determinant) [itex]\tau = (4*F_x + 2F_z) \\ F_z = 0 \\ \tau = 4*6 = (24 N.m) J[/itex] (ignore the difference between 24 N.m and 23.98 N.m, this is just because of the bad precision involved in the calculations) So, I believe that the second method is the correct one (since I directly calculate the determinant), but my question then is, why the right-hand rule fails?