Answer:
1.785 m
Explanation:
Without the worker the scaffolding produces 300N tension in each rope
if worker is in the middle, each rope will support 1/2 of worker's weight (325 N) for a total of 625 N <==== so worker will be pretty close to middle for tension of 660 N
Need 360 N in addition to 300N board
360 * x = 290 ( 4-x)
x = 1.785 meters from an end
Well ....that is kinda the 'intuitive approach'.....maybe this way will be more clear:
The moments around one end have to be = 0 or the plank will move
from the left end moments:
600 ( 2.000) + 650 ( x) = 660 (4.000)
x = 2.215 m from left end or 1.785 m from R end (that has the 660 N tension)