Question About Beginner Static Problems

[lc99]

Homework Statement

Homework Equations

The Attempt at a Solution

I noticed that the units are in mm and i usually would convert to meters for the convention. But, is it okay to leave the mm as is when i calculate the unit vectors since the unit vectors are unitless? I don't want to deal withd decimals in my calculations.

in general, do i ever need to convert my units?

 

[lc99]

Also the calculations get realllly mess real quick. How can i simplify things so that i don't get messy numbers all over the place? I keep finding myself getting the wrong answer because of the mess in numbers.

 

[Dr Dr news]

Don't worry about the units, Just keep track of them by labeling all of your calculations with the correct units. Statics problems are all based on ∑F = 0 and ∑τ = 0. Since F and τ are both vectors the static equilibrium equations represent 6 equations, some of which may not be needed in a particular problem. So set ∑F(x) = 0, ∑F(y) = 0, ∑F(z) = 0, ∑τ(x) = 0, ∑τ(y) = 0, ∑τ(z) = 0. Noting that τ = r x F.