# On a fixed beam, which force induces a counterclockwise torque

Given this situation ($$P$$ is the point where the beam is fixed), which force induces a torque that is counterclockwise? I want to use that : $$\boldsymbol{\tau} = \textbf{r} \times \textbf{F}$$ , however what does counter clockwise torque mean? Intuitionally it would seem that $$F_2$$ would turn the beam around its own axis (counter clockwise) but so would $$F_3$$ and $$F_5$$.

So my question actually is: what does counter clockwise torque mean in the context of this exercise?

Any hints are greatly appreciated.

## 1 Answer

Counter-clockwise means anti clockwise direction.

So this question is asking which force will rotate the rod in anti clockwise direction. • Yes, i know the meaning of the word. But in 3 dimensions there are 3 possible ways to go counter clockwise. What is meant in the context of this exercise? I dont have any experience with physics or engineering so i dont know for sure what is meant here. – zokilokipoki Aug 8 '20 at 0:18
• Imagine the rod to be hour hand of the clock and now think which force(component) rotates the rod in anti clockwise direction. – Danny LeBeau Aug 8 '20 at 0:19
• And how exactly there are 3 possible ways? – Danny LeBeau Aug 8 '20 at 0:20
• xy plane, zx plane and yz plane, and in each you can go clockwise or counter clockwise ; so your comment doesnt really help – zokilokipoki Aug 8 '20 at 0:21
• Is f2 perpendicular to the rod? – Danny LeBeau Aug 8 '20 at 0:22