. why does a object that is traveling very fast (take for example a F-16 at full military power) require a larger turn radius to , turn?
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For your example specifically, there’s a video that I remember watching I think it’s smarter every day on YouTube he or someone he’s interviewing is explaining that the reasons an F-16 or F-35 can’t turn as quick as it would like is restricted upon the pilot. The human body can only take so much. The aircraft itself can do much more maneuverability wise if humans weren’t in the cockpit. I don’t know the science behind it I’m assuming it’s the weight the pilot is pulling (G’s) and some other factors. But those aircraft can turn damn near fast and do some crazy maneuvers if humans aren’t involved and maybe it had an autopilot feature.
Because there is a human inside and humans are not sturdy. To turn tighter would subject the human too more Gs than it can take.
Turning is acceleration (changing velocity). You are changing your northward velocity into eastward velocity; that requires acceleration, which takes time. The faster you’re going, the more time it takes for you to accelerate that initial velocity away, and the more (northward) distance you cover while accelerating eastwards.
Turn acceleration along a circular arc is v^2 / r
So if you are going twice as fast, you’ll require four times the radius to make the turn with the same acceleration.
Planes have an additional problem unrelated to the pilot, but for similar reasons to why the pilot can’t sustain those kinds of turns. The problem for both is G forces.
As you probably know, G forces are really centrifugal forces that *appear* to increase your weight. Your mass wants to continue going in the same direction, but you’re being pulled by the turn into a new direction. That apparent increase in weight is what causes the pilot to pass out – because their blood gets “pulled” down away from their brain. The pilot’s body acts like everything in it weighs two or three or eight times more than it does.
Those same G forces also apply to the jet itself. The whole jet wants to continue going in the same direction, but the lift generated by the wings is trying to yank it in the opposite direction. The more obvious problem with this is that the apparent extra weight caused by the G forces puts a *lot* more stress onto the wings. Just like the pilot, the jet is acting as if it weighs several times more than it does while the wings are continuing to try *really* hard to hold it up. If the turn is too hard, the wings can get damaged or break entirely. The pilot is still the weaker link, though – the plane will hold together through a harder turn than the pilot can.
The less obvious problem is that the wings can only generate so much lift and with the jet’s mass acting much heavier, the wings may not be able to create enough lift. Compounding that issue is the fact that lift is always generated perpendicular to the wings’ surface. That is, gravity is always always pulling straight down towards the ground. During level flight, the lift from the wings is pointed directly up, away from the ground. As the plane rolls into the turn, the lift from the wings is rolling with it. In essence, the plane is turning by rolling to the side and “lifting” itself in that direction.
That means the lift isn’t directly opposite of the force of gravity as the plane rolls. The wings have to create enough lift to continue overcoming gravity and keep the plane flying even though less of that lift is opposing gravity. Again, though, the G forces make the plane *seem* heavier than it is, at least in the direction of the turn. By rolling to the side more, the plane uses more of its lift to *turn* and less to *fly*. The harder the plane turns, the more it has to roll, and less of the lift is opposing gravity. If the plane turns too hard its wings won’t be able to create enough lift to both turn and fly, and the plane will stop flying. That’s not *terrible* if the plane is high enough – it can drop a bit as it turns, as long as it has a safe margin before it will run into the ground or anything else.
Try it by going out to a field and marking a spot. If you walk up to the spot you can change directions very quickly. Now try running up to the spot at a fast pace. To change direction takes a few steps.
Aside from the G Loading on the pilot and airframe (i.e. the force on them and how much they can survive) one factor no one so far has actually mentioned is the Lift. Wings on an aircraft cannot produce an infinite amount of lift, but you need lift to turn.
If you want to fly a 9G turn you need the wings on your plane to generate 9G of centripetal acceleration. So if your plane weighs 1 ton but the maximum amount of lift the wing can generate at top speed before stalling is only, say, 7 tons, then you cannot physically fly a 9G turn in that aircraft, because it is incapable of even providing the turning force to maintain it.
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