Solution 2.9b
From Mechanics
In part a) the weight of the man at the top of the mountain is found to be 785 N.
At sea level \displaystyle g=9\textrm{.}81\text{ ms}^{\text{-2}}, and his weight is \displaystyle mg giving \displaystyle 9.81\times 80=785\text{N}
The difference is negligible and variations due to the fact that the earth is not perfectly round (spherical) create a larger error than the above approximate calculations.
