When wading across a stream or river for example. I want to know how the force of water varies according to its depth and velocity of flow. And are there any other factors that affect the force exerted?
2006-07-21 20:51:43 · 2 answers · asked by dwmcloda 1 in Science & Mathematics ➔ Physics
I think you are talking about inertial force, this is a very complex problem and there is no general Formula for it. It is a very dynamic system of variables. Engineers usually deal with a problem of this complexity by testing in laboratory conditions and building a set of tables for reference.
Once you have such a table, you would multiply by the depth and square by the velocity. If the magnitude were great enough the density of the fluid at greater depths would also be important.
2006-07-21 21:07:50 · answer #1 · answered by Sleeping Troll 5 · 0⤊ 0⤋
The force depends on the velocity of the water (I'll give the formula presently), the surface area on which the water impinges, and on the shape of the object in a manner which is too complex to be given by a simple formula.
Suppose that you have an object of area A in a fluid stream of velocity v such that the fluid is brought to a complete stop at the boundary layer. The mass of the fluid striking A is v times A times rho (the density of the fluid). The momentum transferred is v times the mass. Hence the pressure is A times rho times v squared. This ignores streamline effects, which can cause the answer to be very different.
2006-07-22 04:11:03 · answer #2 · answered by Anonymous · 0⤊ 0⤋