a 650-n billboard worker stands on a 4.00-m scaffold weighing 600 n and supported by vertical ropes at each end. how far would the worker stand from one of the supporting ropes to produce a tension of 660 n in that rope?

Respuesta :

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)

Ver imagen jsimpson11000