Another interpretation of equation (23) may be useful. Consider the situation where the
sliding mass of material acquires somehow a velocity V relative to the ground or foundation.
This velocity may be imparted by motion of the foundation and that part of the dam which
presses against the sliding wedge, but in any event, it is the velocity of the mass, relative to the
ground or foundation on which it slides, that is needed. This is not necessarily the same as
the maximum ground velocity.