So that we do not contaminate it with microorganisms or garbage or other human stuff.
Work done is equal to force by distance; so you take the force exerted, in newtons, and multiply that by the direction it's moved (from the starting point in a line, not along the path it's taken.)
It depends because it’s might be lolilolololol 21212132
Linear expansivity, area expansivity and volume or cubic expansivity are
F = ma
We have mass = 0.2kg
and acceleration = 20 m/s^2
So..
F = (0.2)(20)
F = 4 N