Blaise Pascal, the 17th century French mathematician, physician and philosopher, stated the following law:
The pressure applied to a point in
an incompressible fluid at rest in a closed container is transmitted
equally to all the points in the fluid.
If you exert a force F on
a bulb with a cross section S, you cause a pressure (p = F / S)
which is manifested in the whole of the liquid mass. Pressure is a
scalar magnitude, but the force which creates it is a vector which is
perpendicular to the surface on which it is acting. So that in a
syringe it is perpendicular to the side walls, the bottom and also the
bulb which compresses the liquid.
Observe in the visual below how the
liquid comes perpendicularly from each of the holes. The speed of flow
is the same from all of the holes.
