Physics bros come

I am having trouble deciding the sin and cos component for free body diagrams. I need to know if vertical or horizontal is sin or cos and if it changes with respect to vertical pov or horizontal pov

depends on which angle u are taking the sine or cosine of

if the angle you're given is between the force and the 'x axis':

horizontal -> cos
vertical -> sin

if the angle you're given is with the 'y axis', then:
vertical -> cos
horizontal -> sin

it takes practice but you can do it without thinking once you get used to it

soh cah toa is your friend

i'm serious, just draw the triangle (if you can) and see which one applies to the angle and vector you're given

it'll become second nature after a while

they way i was taught is that if you are going through the angle when resolving then it is cos, and if you are moving away from the angle it is sin. for example if we're thinking about the vertical reaction force of an object on a slope, we do the cos of the angle of the slope as to move from the direction of the reaction to the horizontal we move through that angle

Use chatgpt if confused

You got this

Thank you everyone for helping
I have done the problem.