right hand rule
posted by jen .
i hope this makes sense.
Say that i have x and y axis. then i have an arrow coming out similiar to how you would draw a resultant arrow in physics.
the arrow represents Force=140N
Then say that you have to find the moment about O and the origin is O.
So the first step is to find Fx and Fy.
Then you use M=Fd to solve the problem but you also have to use the right hand rule to figure out the direction for each force and distance.
Say that Fx=4i. I know to find the direction you do rXF. But when i use the right hand rule, after i put my hand in the r direction, do i curl my finger in the F direction or the Fx direction.
also i have solutions to my textbook. Sometimes they say that clockwise is positive and counterclockwise is positive. How do you decide whether each is positive or not. I thought usually, counterclockwise was positive