maths Help!!

Hi guys,
would just like to ask how in mechanics, the direction of motion of connected particles is found, I know you assume the equations and if I think acceleration or tension is negative then its the opposite really unsure.
Thanks for your help!

Bump

Original post by Username123455

Generally you choose
* a global positive direction (generally done to keep things as positive as possible)
* set up the equations with a best guess about the sign (direction) of the variables youre calculating
* when you solve, if they are positive, you guessed well. If they're negative, then the velocity, acceleration, force, ... is in the opposite direction.
Upload a question with your working if youre unsure.