John carry the heaviest load.
<h3>How to find out who is carrying the heavy load?</h3>
Write down given data from questions:
Board=510cm X 510mm.
Cylinder head with dimensions=43cm X 250mm.
Cylinder lies across the board 210cm from john.
Find out: Who is carry the heaviest load?
Calculation:
We assume that mass of cylinder head = x kg
Then weight=x x 9*81
W=9.81x Newton.
Weight per unit length= Weight/Total leanth
Weight per unit length= 9.81x/43
(w/l)=0.23x N/cm
From equation contition: 
(210+21.5)




Therefore 
To learn more about mass per unit length, refer to:
brainly.com/question/24180692
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