The minimum pulling force required to start it moving is
equal to the static frictional force.
F = (mass) x (gravity) x (coefficient of static friction).
Once it's moving, the force required to keep it moving at a steady speed,
without speeding up or slowing down, is the force of kinetic friction.
F = (mass) x (gravity) x (coefficient of kinetic friction).
In both equations, [ (mass) x (gravity)] is just the object's 'weight'.
