velocity pressure?

Answer 1

Do you mean the relationship between velocity and pressure? According to the Bernoulli Principle, pressure drops with an increase in velocity. This is evident in many practical aspects of life.

For instance, the desire of your shower curtain to float into the shower towards the stream of water exists because the fast moving water coming out of the shower speeds up the air movement inside the shower as well. With that increase in velocity, the pressure drops, creating a pressure differential between the outside of the shower curtain and the inside (outside being greater) thus pushing the shower curtain in.

Another, and perhaps the most important example is the ability of an airplane to fly. Airplane wings, if cut in cross section, are curved on top so that the air speeds up as it passes over the wing. With the increase in velocity comes a decrease in pressure, therefore once again we see a pressure differential between the air on top of the wing, and the air below. The air below having greater pressure, pushes up on the wing giving the wing what we refer to as lift!

Answer 2

Velocity head in a pumping system is an energy component that represents the kinetic or "velocity" energy in a moving liquid at the point being considered in the system. It is equivelent to the verticle distance the mass of liquid would have to fall (in a perfect vacuum) to aquire the velocity V and is expressed as:
h(subv)=V(squared)/2*g=.0155V(squared)=.00259(gpm)(squared)/d(fourth power)=.00127(bhp)(squared)/d(fourth power)
where:
h(subv)=velocity head in feet of liquid
V=Velocity of liquid in Ft/sec
d=inside diameter of pipe in inches
g=gravitational constant 32.174 ft/second(squared)
gpm=US gallons per minute
bhp=barrels(42 gallons US) per hour
The velocity head energy component is used in system head calculations as a basis for establishing entrance losses, losses in valves and fittings, losses at other sudden enlargements and exit losses by applying the appropriate resistance coefficient K to the V(squared)/2g term.

Answer 3

velocity is different from pressure.
an example of velocity is feet traveled per second or miles per hour.

Pressure is psi or pounds per square inch.

I am not sure of your question.

Answer 4

0.5 C * V^2 where C is the drag coeffcient