Answer:
579600J
Explanation:
Given parameters:
Height of the building  = 828m
Weight of the man  = 700N
Unknown:
Work done by the man  = ?
Solution:
The work done by the man is the same as the potential energy expended.
 Work done:
       Work done  = Weight x height  = 700 x 828
    Work done  = 579600J
