Why does the force of wind only depend on its speed?

Question

For instance, a light car versus a heavy car going at the same speed have very different amounts of kinetic energy. Why is wind only based on speed?

Answer 1

not true, it also depends on the density of the wind (air). same as with the "density" of the cars.

At the same wind speed very dense air has more kinetic energy then very "thin" air would have. In the high atmosphere (10 miles up) winds regularly reach 100 mph but due to the low atmospheric pressure they would do very little harm.

But since atmospheric pressure does not vary that much at ground level one can for the most part ignore the density of the air and focus purely on wind speed.

Answer 2

Because it isn't? It depends on the wind density too. Your kinetic energy thing depends on the difference in mass between the cars - same thing applies to wind, a heavy mass of air flowing at a given speed exerts more force than a lighter mass of air moving at the same speed.

Answer 3

Wind is a product of differences in air pressure. The wind is simply air moving from a higher pressure area to a lower pressure area. The greater the pressure difference, the fasterthe movement.

The "force" of wind is the volume of air moving through any space. Faster wind means more air moving through that space. But the speed is simply a result of the pull of the lower pressure area. Effectively, wind is sucked, not blown.

Wind is measured by speed because it's easy, but technically, we are measuring volume. The paddles of the anemometer move faster as more air volume moves past in the same amount of time. Another indicator of wind is a barometer. As pressure falls, you can expect some wind. The faster the drop, the more wind. That's why they write "Stormy" on the left side of the dial.

Answer 4

The equation used for all of those sorts of calculations is the final equation of curvilinear action: x(t) = x(0) + v(0) * t + ((a million/2)(a)(t^2))) the place: x(t) is the area coated at time t x(0) is the preliminary distance/area (in lots of cases 0) v(0) is preliminary velocity (0 if dropped from a height and not thrown down) a is acceleration (in a vaccum that's 9.8m/sec^2 on earth) considering you prefer velocity and not distance, we can use problem-unfastened algebra to reorganize the equation and simplify it to: v(t) = v(0) + ((a million/2)(a)(t^2)) or in written variety: the cost of an merchandise at any time t often is the sum of its preliminary velocity (0 if dropped extremely of thrown down) plus the rate gained by way of acceleration (in a vacuum). lower back this assumes wind resistance does no longer play an element interior the falling merchandise. If it does (its no longer sparkling out of your question) then this equation isn't top, and issues get very complicated (think of faculty point or graduate point extremely of highschool point answer).

Answer 5

look up mach speed (Wiki, Google) to give you insight on altitude.

My best answer in this case is to consider the inertia factor. The propensity of an object in motion to stay in motion. Let's consider the light/heavy car at equal speed (velocity). Well presumably it took more effort to get the "heavy" car up to speed than the "light" car. And accordingly the heavy car would have the kinetic advantage if all else is equal...namely friction and drag.

Answer 6

So you've partly answered your own question. Like the cars, wind pressure is a function of density and speed. This shows the standard equation for large velocity drag:

http://en.wikipedia.org/wiki/Drag_%28physics%29#Drag_at_large_velocity

Answer 7

Because even though its density changes slightly with weather conditions, the density is relatively constant.

So given the constant density, the force will only depend on speed

Answer 8

Because of its density, surrounding Temperature & Direction of the wind

Answer 9

BTW, what do light and heavy cars have to do with wind force....?!!

Answer 10

it doesnt. It also depends on the density of the air