Another rant...

Went for my mechanics lab today...lost a few marks thanks to my lecturer. That said let me show you why me took marks off my lab.

This is a question about moments where you have to write an equilibrium equation for it

So, I drew a picture of this:



and wrote my equation as (W1)(A)=(W2)(B)

Think it is right? Nope.... Why you say? His answer was

You have to write it like this:
A = Distance to centre/fulcrum from W1
B = Distance to centre/fulcrum from W2

Equilibrium equation, (W1)(A)-(W2)(B)=0

WTH!? Isn't that what I wrote. But thanks to that I lost some of my lab marks.

Man this kind of ppl >_>