Answer:
Therefore it is save to carry a 62kg adult
Explanation:
From the question we are told that:
Mass 
Height of supporting Rock 
Length of Board
Mass of board 
Mass of adult
Generally the moment of balance about wedge part about is mathematically given by



where

therefore

if N=0 at fallen person

Therefore it is save to carry a 62kg adult
Well it does carry blood and oxygen! Sorry but I'm not sure about 2 and 4.
Answer:
55.56kg
Explanation:
Given:
F= 52N
a=0.936m/s²
Applyinc Newton's second law, that states: force is equal to mass times acceleration.
F = ma
m=F/a =>52 / 0.936
m=55.56kg