(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Hi

I have a physics exam tmorrow and I was hoping I could get a little help with the moments problem. I attached the drawing and the question asks:

a-1. State the principle of moments

b-1.Write down expressions including W, Rc and FA for

(i)the total counter clockwise moments about pivot B

(ii)the total clockwise moments about pivot B

(iii)what is the value of Rc when the first boom loses contact with its cradle

2.Use the results in 1. (i),(ii) and (iii) above to find the mass of the counterweight that must be used if FA=25N is just enough to start raising the boom (g=10ms-2)

2. Relevant equations

3. The attempt at a solution

a-1 the principle of moments states that for a system in equilirium the sum of the clockwise moments is equal to the sum of the anitclockwis moments

b-1(i)600N X 6m=3600Nm

And we were never atught how to answer the rest so from there i'm lost.Help plz

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Questions about principle of moments

**Physics Forums | Science Articles, Homework Help, Discussion**