It seems this isn't a word... When I try to look it up, I only get results that define 'accelerate' or 'decelerate.' I'm looking for the word that means 'to increase in speed but at a slower rate than previously' or 'not increasing as quickly as before'. What is the correct word for that? I understand it is still 'acceleration', but it seems that there should be a word to describe when something is 'accelerating less.'
ya, kinda. jerk is the unit of measurement that measures that which I'm refering to. Tho I don't think if I were to describe something 'de-accelerating' to someone as 'jerking' they would understand would I'm meaning...
probably, but aiui creeping is a far more complicated dynamic whereby acceleration/deceleration warps time relativity. so while 'de-acceleration' certainly factors into creeping, creeping is not the right word to describer what I'm talking about.
This all started when I was having a discussion with a friend about space-based kinetic weaponry, sometimes refered to as 'rods from god'. The theory (i use 'theory' loosely as its very unlikely that such weapons don't already exist) is that a large 'rod' of a hard, dense material such as tungsten or depleted uranium, if dropped from high orbit, would achieve a high terminal velocity (due to large weight and low atmospheric drag) and would experience very little 'de-acceleration' once it hit atmosphere. The theoretical energy released on impact of, say, a telephone pole sized rod of tungsten dropped from high orbit would be similar to a tactical nuke. It also would not have any leftover radioctive particles, not violate the 'no nukes in space' treaty and be impossible to deflect/destroy with any known missile defense systems. ...the discussion was long sidetracked by a debate over what to call what the 'rod' does when it hits atmo and begins to reduce in acceleration.
Friction is typically the cause of 'de-acceleration', but I believe gravity can also cause it in certain circumstances, so I don't think 'friction' is the right term either.
peak trajectory seems to refer to the maximum height of the arc of an object launched from gravity before it succumbs to that gravity and returns, so no, not what I'm looking for.
Jerk is the rate of change of acceleration. It is the third derivative of position as a function of time. Acceleration is the second derivative. Velocity is the first derivative. Reduced acceleration... I don't think there is a single word for that. There is a negative jerk when acceleration is reduced.
That diagram has an active slowing component where it says "de-acceleration". BUT, the fact that the acceleration is in a different direction doesn't mean it isn't an acceleration. It doesn't get to have some new name. Acceleration has a directional component. The flight of the spacecraft is guided by the sum of all accelerations - onboard power, gravity of all mass throughout the entire universe (though distant mass has little impact on rockets and gets ignored in rocketry, but not cosmology), friction, etc.
The velocity is still increasing. De-acceleration is when the velocity starts to decrease. Acceleration means the second derivative is positive. De-acceleration means the second derivative is negative. But technically we never use the term de-acceleration. That is a pedestrian term. It is all just acceleration.
The negative sign just indicates the direction of the acceleration. Acceleration is not a scalar. Gravity is an acceleration toward the center of mass, for example. If an object is slowing, there is some acceleration being applied - gravity, friction, motor, or whatever. In fact, the acceleration as felt by the object (rocket?) would be the sum of all accelerations acting on the body - something to think about if you're trying to send a rocket to land on some moon of some planet.
I agree with your last sentence. Still, I would say that if velocity is decreasing a better pedestrian term would be that the rocket is "slowing".
i like diminishing acceleration. I dont like it as much as de-acceleration... but it prolly conveys the idea better.
Yes, deceleration is identical to negative acceleration. That is not what you are talking about [Oxford Dictionary] de·cel·er·a·tion /dēˌseləˈrāSH(ə)n/ Learn to pronounce noun reduction in speed or rate What you are talking about is the speed or rate [magnitude of the velocity] increasing less quickly, not decreasing.
