Understanding Free Body Diagrams

free body diagram — sounds dead posh, but it’s just drawin’ a picture of all the forces bashin’

on a thing. First job, you sketch the object, nice and simple, box or blob,

don’t need Picasso. Then you chuck arrows on it for every force you reckon’s actin’ — gravity

down, reactions up, maybe a push or a pull sideways. Now the maths bit

ain’t scary. Each arrow’s got a magnitude and a direction, so you split ‘em

into components — usually X and Y. Add ‘em up, job’s a good ’un.

If it balances, the thing’s sittin’ still. If not, it’s shiftin’ or

bendin’. So the setup’s dead easy: draw the body, mark the forces, break ‘em into axes,