D.) In order to calculate both of them, we must know the "FORCE" on the system.
Rutherford's model of the atom (ESAAQ) Rutherford carried out some experiments which led to a change in ideas around the atom. His new model described the atom as a tiny, dense, positively charged core called a nucleus surrounded by lighter, negatively charged electrons.
Answer:
2.5 m
Explanation:
Weight of billboard worker = 800 N
Number of ropes = 2
Length of scaffold = 4 m
Weight of scaffold = 500 N
Tension in rope = 550 N
The sum of the torques will be
![-800(4-x)-500\times 2+550\times 4=0\\\Rightarrow -800(4-x)=500\times 2-550\times 4\\\Rightarrow -800(4-x)=-1200\\\Rightarrow -x=\dfrac{1200}{800}-4\\\Rightarrow -x=-2.5\\\Rightarrow x=2.5\ m](https://tex.z-dn.net/?f=-800%284-x%29-500%5Ctimes%202%2B550%5Ctimes%204%3D0%5C%5C%5CRightarrow%20-800%284-x%29%3D500%5Ctimes%202-550%5Ctimes%204%5C%5C%5CRightarrow%20-800%284-x%29%3D-1200%5C%5C%5CRightarrow%20-x%3D%5Cdfrac%7B1200%7D%7B800%7D-4%5C%5C%5CRightarrow%20-x%3D-2.5%5C%5C%5CRightarrow%20x%3D2.5%5C%20m)
The position of the person will be 2.5 m