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

Aayan [#3]

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

Will the sin and cos change if theta is with vertical and theta is with horizontal in the same scenario

Denjisideals [#5]

Will the sin and cos change if theta is with vertical and theta is with horizontal in the same scenario

can you illustrate your question? I don't quite understand

Aayan [#6]

can you illustrate your question? I don't quite understand

It's a situation of pseudo force from a viewer's pov inside a car moving with constant a as he watches a weight hanging from the top of the car

Aayan [#6]

can you illustrate your question? I don't quite understand

wait I think I understood, here's a crude paint drawing to explain
https://i.imgur.com/B5wpckD.png
here's a more clear version:
https://i.imgur.com/eV8Xt6q.png

Denjisideals [#8]

It's a situation of pseudo force from a viewer's pov inside a car moving with constant a as he watches a weight hanging from the top of the car

see #7, tell me if that explains it or if I misunderstood

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

bonkashi [#10]

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

yeah this is a good explanation
if the angle is on the same side as you're resolving its cos, if its not its sin

Use chatgpt if confused

Aayan [#9]

see #7, tell me if that explains it or if I misunderstood

Yes it makes sense
Thanks

Aayan [#7]

wait I think I understood, here's a crude paint drawing to explain
https://i.imgur.com/B5wpckD.png
here's a more clear version:
https://i.imgur.com/eV8Xt6q.png

In general, is cos vertical or horizontal

You got this

Thank you everyone for helping
I have done the problem.