Friday Official Update, July 20, 2012

[Wolf_Rider]

Originally Posted by Blackdog_kt

In some bombsights it was called trail (i don't know in what values they measured it), in some later RAF sights they would input the bomb's terminal velocity and now i learned that in the Lofte it was called Rücktriftwinkel and it compensated wind resistance through the drop.

What amazes me is how our friend Heinz realized this is missing, since there is no clear way to test for it. Eg, we would have to make our own bombing practice range in the FMB with objects at preset distances, to see that they impact short by specific distances each time.

Determine the weight of the falling object. The easiest way to do this is usually to measure this quantity directly. You can also estimate weight if you know the construction materials and dimensions.

2
Calculate the frontal area of the falling object. The frontal area is the apparent area facing in the direction of falling. You can determine this area by measuring the outline of the object from that orientation. For example, if the falling object were a cone, the tip of the cone would point straight downward, and the frontal area would appear to be a circle equal to the area of the circular base of the cone.

3
Determine the drag coefficient of the falling object. You can usually avoid having to calculate the drag coefficient yourself by looking up an approximate value in a reference book or on the Internet. If you need a highly precise value, you should consult with an engineer.

4
Determine the gas density of the medium through which the object will be falling. If the medium is the air, then you should know that air density decreases with altitude, which means that the object's terminal velocity will decrease as it gets closer to the ground (where the gas is denser and pushes back harder, providing stronger braking power). Thus you can calculate terminal velocity at any one altitude using simple mathematics, but to calculate the change in the terminal velocity over a long-distance fall, you will require the use of calculus or empirical approximations. Air density also changes with the weather; there is no uniform density value for a given altitude. To get the most accurate measurements of air density, you will need to multiply average air density values by local weather condition offsets. Atmospheric information is available in the United States from the National Weather Service, a service of the National Oceanic and Atmospheric Administration.

5
Calculate terminal velocity at a given altitude with this equation: Terminal V = sqrt ((2 x (Object Weight)) / ((Frontal Area) x (Drag Coeff.) x (Gas Density))).

In plain English, the terminal velocity of the object is equal to the square root of the quotient of twice the object's weight over the product of the object's frontal area, its drag coefficient, and the gas density of the medium through which the object is falling.



Read more: How to Calculate Terminal Velocity | eHow.com http://www.ehow.com/how_6134922_calc...#ixzz21SPSlnUQ