Because mass and distance determine gravity, so the more mass you have, the more gravity.
You would want it to be greater than D. friction force
It needs be greater than the friction applied to it.
You could use a magnetic generator or you could use hydraulic power
That would be a frequency of 1.2666... beats per second. This can be phrased as your heart beats at 1.27 Hz.
It is commonly perceived as "thickness", or resistance to pouring. Viscosity describes a fluid's internal resistance to flow and may be thought of as a measure of fluid friction. Thus, water is "thin", having a low viscosity, while vegetable oil is "thick" having a high viscosity.
