Tbh i dont fully understand the Coriolis Effect either, i only understand that it makes wind blow in different directions depending on your latitude but i dont know why.
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When it comes to a projectile, the Coriolis Effect has nothing to do with the wind, it has to do with the rotation of the Earth.
If a projectile spends too much time off the ground travelling, the Earth will travel underneath it, and it will no longer be headed toward the same target it was going for when fired – from it’s perspective, everything will be moving laterally (IE. side to side).
From the perspective of the target/person firing the projectile, the projectile will be arcing in the opposite direction of the planet’s rotation (or the opposite, depending on the direction fired). Essentially, it’ll look like the projectile is turning away from the target.
Wind is an entirely separate issue that can also effect the projectile’s path.
The “drift” is because the target is standing (and therefore moving with) a rotating Earth, while the bullet, once it leaves the barrel of the gun, is free of Earth’s rotation. The bullet moves in a linear path; the air that is moving with the Earth is not providing enough resistance/force to bring the bullet along with it (which is good for the shooter, because if air resistance was that strong, bullets wouldn’t be able to fly **through** air like they do, making them useless). That means that, to the shooter or observer, the bullet may appear to drift sideways, with the direction dependent on the direction of the shot relative to the direction of the Earth’s rotation.
Yes. In fact, it would affect the bullet trajectory even in a vacuum.
Suppose you’re standing at the equator, where the Earth is rotating at a speed of about 1,700 km/h. You, your gun, the bullet in your gun, and anything else at rest with respect to the ground are rotating along with it. You fire your gun away from the equator – let’s say northward – and let’s imagine for the sake of clarity that your bullet is traveling over a big fraction of the Earth. The movement of your bullet relative to an observer floating above (but not rotating along with) the Earth has an east-west component of 1,700 km/h eastward, and a north-south component of <whatever the bullet’s speed is> northward.
When your bullet reaches 30 degrees latitude, traveling northward along the Earth’s surface, it’s now over land that is rotating more slowly. Why? Because it has less ground to cover. The higher your latitude, the smaller of a circle you have to traverse in 24 hours (or more properly, 23 hours and 56 minutes, but that’s another thread) to go around once. At 30 degrees latitude, the distance is cos(30 degrees) = sqrt(3)/2 = about 70% the speed it is at the equator. Now the ground is moving eastward at ~1,200 km/h eastward relative to our floating-but-not-co-rotating observer. **But your bullet is still moving at 1,700 km/h eastward** – why wouldn’t it be? Nothing acted to change its movement.
Thus, **relative to the ground**, your bullet would now be traveling eastward at 500 km/h. This is the Coriolis effect: it’s a consequence of things moving from a part of the Earth that is rotating more quickly to a part that is rotating less quickly or vice-versa. It has nothing, directly, to do with the air, although the Coriolis effect *on* air is quite important to Earth’s weather.
Yes. Even if the air is still relative to the ground (no wind), the air at different latitudes is still moving at a different speed to cover the different distance in order to make one revolution in one day.
The world is roughly a sphere that’s rotating; visualise a globe spinning on its axis. Now imagine what would happen if something on the earth’s surface started to go in a straight line, rather than being stuck to the surface. The difference in the straight versus the circular path is what causes the Coriolis effect, both for bullets and for the air.
The nearer you are to the poles, the more the effect causes bullets to drift to the right (in the Northern Hemisphere) or to the left (in the Southern Hemisphere); there’s no such effect at the equator. The nearer you are to the equator, the more eastbound bullets drift up and westbound bullets drift down; there’s no such effect at to poles.
The Coriolis effect is a big contributor to the way the winds blow, and winds obviously affect bullets in flight, but this indirect effect is not what people mean when they talk about Coriolis and ballistics.
Coriolis effect is not reliant on wind, the wind is affected by the coriolis effect as is any other object moving in a north or south direction and the Eötvös Effect when east or west(noticable only with bullets). For the coriolis effect this effect happens because of the spinning earth and your starting position. If you start at the pole and move really quickly to the equator the ground will be moving to the east at 1000mph so to a person living at the equator will see you moving to the west at the same speed. It’s basically the difference in spinning momentum with objects at different points of the earth. Object that move across the earth fairly quickly(planes, air, bullets) dont change momentum fast enough so you see the difference in momentum as a visual curve in their path.
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