# Tagged Questions

Jerk is the third derivative of displacement with respect to time. It is also the derivative of acceleration with respect to time.

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### What really is force? [duplicate]

I know the second law of Newton says $F=ma$ which seems to me the most fundamental expression of the force. In other words, force cannot exist without a "forced" one. It is somehow a "secondary" being,...
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### How is the Dirac delta function used in classical mechanics? [closed]

If the contact force applied to a physical object (ex. empty bucket) is given by the Heaviside function: $$F(t) = F_0~H(t)=\begin{cases} 0, t<0 \\ F_0, t \geq 0\\ \end{cases}$$ Then,...
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### From a displacement-time table/graph, can one tell whether acceleration or jerk is constant?

Does constant acceleration equal a parabolic graph similar to $y=x^2$, while jerk follows the path of $y=x^3$? I was just thinking about this possibility. We are always told in physics class that ...
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### Position, velocity, acceleration, jolt, and [duplicate]

I am familiar with the fact that $\displaystyle{\frac{dx}{dt}}=v$, $\displaystyle{\frac{dv}{dt} =a}$, and $\displaystyle{\frac{da}{dt}=J}$ where $J$ denotes the 'jolt', or jerk. Are further ...
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### Relationship between velocity and position due to constant jerk proof check [closed]

In constant accelaration and linear (1D) motion, we can show that relationship between velocity and position is quadratic (parabola) by We can write $v$ in the form of $v=v(x(t))$ a=\...
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### Physics of Auto Crashes and Airbag Modules

I recently saw a post (that was pretty old) asking why we don't consider the jerk function more often in sciences that deal with impacts or sudden accelerations. The general belief was that impacts, ...
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### Calculating travel time based on distance, velocities, acceleration, and jerk

Not much physics background so please bare with me. Say we have an object traveling on a straight line going from x to y. We know the starting velocity at x, the velocity when y is reached, the max ...
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### Force felt by parachutist when opening the parachute [closed]

When falling down with air resistance, y-axis vertical (positive is up), x-axis is horizontal, we have that: $F_y=-mg-kv=ma_y$, where $k$ is the drag coefficient. Now if the man opens the parachute, ...
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### Using constant snap, what acceleration is required to achieve a desired change in position, with acceleration and velocity bounded

Also assuming you must approach the bounds of acceleration and velocity smoothly -- i.e. their derivatives approach zero as you reach the bounding value. In some cases, you may not reach the bounds ...
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### Higher order versions of momentum? Can conservation principles be established and used? [closed]

Question Can higher order derivatives of momentum be useful in creating theories of dynamics if they have conservation principles? Even if they aren't needed, could it be done in theory? For instance,...
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### How to sensor Jerk=$d^3{\bf r}/dt^3$, or higher derivatives (4th, 5th, 6th order) when applied in the equation of motion of a ballistic missile?

Given a 6th order differential equation of motion as usually used in ballastic missile dynamic models. What kind of sensors are usually used to measure Jerk, (or higher order derivatives in kinematics)...
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### finding velocity along a curve with kinematic equations using time

(i'm "not" looking for coding help. i need help setting up the math.) i'm writing a program for a physics class to find the velocity of an object across a random curve. where the only force acting on ...
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### Pushing down on the gas pedal of a car a good example of jerk?

I'm trying to think of the clearest examples to demonstrate the concept of jerk to a layman. Ignoring drag and making other reasonable assumptions (friction is conveniently there to only allow you to ...
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### Constant Jerk Relativistic Rocket [duplicate]

A quick google search will give many helpful pages and calculators regarding constant acceleration relativistic rockets, but my question is somewhat different. What if jerk is the parameter to be ...
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### Instantaneous cause [closed]

The position of an object has a rate of change called velocity. The velocity of an object has a rate of change called acceleration. Force applied is proportional to the acceleration of the body (...
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### Appearance of the Jerk Term in Dynamics of Mass-Spring-Damper System

I am coming from the computer science territory and have not a long trace in mechanics. My background in derivation of the system dynamics could be summarized with utilization of the ...
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### Example of a physically motivated jerk equation

When I say jerk equation, I mean a differential equation of the form: $\frac{d^{3}x}{dt^{3}} = f\big( x(t), \frac{dx}{dt}, \frac{d^{2}x}{dt^{2}} \big)$ I am doing some work in dynamical systems, ...
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### How are the higher derivatives (jerk, jounce) of position with respect to time used in physics?

I don't see them much in any physics lesson or course, but that's probably because I'm not into physics as much. I can understand why velocity and acceleration are useful, but why would someone want ...
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### Computing distance traveled from jerk

When dealing with higher time derivatives like jerk, how does one find the distance traveled? Can it be calculated by just knowing time?
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### Why isn't all of physics based on other rates of change [duplicate]

Define the jolt/jerk to be $$J(f)={{d^3 f} \over {dt^3}}$$ Why don't we use the concept of jolt more often considering that the change in acceleration is most definitely an important characteristic ...
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### Is there any such thing as a change in acceleration (ex: 3 m/s/s/s)? [duplicate]

If there exists something like that, then in $distance/time/time/time$, how is it expressed?
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### Calculating jerk vs Fitts law for smoothness

I've tracked the movement of an input method resulting in this dataset. All data is tracked with equal intervals of 100ms. For example an iteration value of 4 means that this is the position of the ...
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### Why don't we consider jerk in physics classes? [duplicate]

When i got more into physics, i started asking myself if just like acceleration represents the growth of speed, something else could also represent the growth of acceleration itself. And it came that ...
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### Why isn't jerk necessary?

I've recently thought about the rate of change in acceleration and found out that is exists and is called jerk. I've looked at some questions and answers but i could not understand something in this ...
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### What are the equations for motion with constant jerk?

Every one knows the three famous equations for motions with constant acceleration . But what if the motion were having a jerk? How should then be the equations for motions? How can I find them?
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### High speed does not kill. Does acceleration do it ? or jerk?

In a recent question the OP asked why high speed will not kill us. The accepted answer, highly upvoted, stated very first that Speed doesn't kill us, but acceleration does. The second answer (...
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### What is the jerk due to gravity with ascent? [closed]

Acceleration is defined as the rate of change of velocity with time. Jerk is defined as the rate of change of acceleration with time. What is the jerk due to gravity with ascent?
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### Is it possible to have a rate of change of acceleration?

I know this may seem a weird question, but it always bothers me. My physics book (Resnick,Halliday,Walker), and also various sites never say anything beyond acceleration. But when a moving body is ...
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### What is the best path for a given initial and final state?

I am trying to calculate an efficient acceleration curve given starting and final positions and velocities. I'm assuming no friction, and that the acceleration can be applied in any direction at any ...
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### When motion begins, do objects go through an infinite number of position derivatives?

This might be a very vague and unclear question, but let me explain. When an object at rest moves, or moves from point $A$ to point $B$, we know the object must have had some velocity (1st derivative ...
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### Frames of reference: Inertial and accelerated - and jerked, snapped, crackled and popped?

There are inertial frames of reference and the accelerated frames of reference, but are there any frames of references w.r.t. higher order derivatives of velocity? [1] [2] For example, jerked frames ...
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### Accelerating fluid filled container [closed]

A container filled with fluid is accelerating initially with a1 and instantly changes to a2 (a2 < a1). What would happen to the fluid in the container. My thoughts on this - If the velocity of ...
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### How do I calculate the distance a ship will take to stop?

I am a River Pilot and drive ships for a living. These ships are very large and range up to 160,000 Metric Tons. I am trying to figure out how to calculate the distance to stopping. I have a basic ...
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### When we take time derivative of a function of time, then is the result another function of time, again?

(I'll try to explain my question by one known example), for example where the velocity is a function of time v(t) then its time derivative (which is acceleration: $a=\frac {dv}{dt}$) is another ...
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### Is there any case where one would use, snap, crackle or pop? [duplicate]

As we all know, if you differentiate distance with reference to time, you get speed, and likewise, differentiating speed you get acceleration. However, if you keep differentiating, to the rate of ...
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### What is the meaning of the third derivative printed on this T-shirt?

Don't be a $\frac{d^3x}{dt^3}$ What does it all mean?
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### Stresses in asteroid during close flyby

The acceleration of an asteroid (such as 2012DA14) as it approaches earth is proportional to the reciprocal of distance $r$ from earth center, squared. the derivative of the acceleration, or jerk, is ...
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### In mechanics, is shock really better expressed as jerk instead of acceleration?

Some expensive electronics or mechanical devices are designed to be shock-resistant. However, the manufacturers often market the level of shock-resistance in units of g-force (I know g-force is really ...
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### How to brake 'beautifully'?

Sometimes when I'm driving my car, I play a "game" against myself in which I try to minimize the deceleration felt by passengers (including myself) while still braking in a reasonable short space. I ...
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### Is there any case in physics where the equations of motion depend on high time derivatives of the position?

For example if the force on a particle is of the form $\mathbf F = \mathbf F(\mathbf r, \dot{\mathbf r}, \ddot{\mathbf r}, \dddot{\mathbf r})$, then the equation of motion would be a third order ...
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### Non-zero higher time derivatives of position?

My mom told me to use speed control, which would allow the car to remain at constant speed. I told her that its impossible for a car to maintain constant speed, as slight changes in friction on the ...
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### Physical intuition for higher order derivatives

Could somebody give me an intuitive physical interpretation of higher order derivatives (from 2 and so on), that is not related to position - velocity - acceleration - jerk - etc?
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### Jerk Magnitudes and Earthquakes

Destruction from earthquakes depends on many factors, including magnitude, occurrence depth and closeness to epicenter. One measure that may relate destructive force for buildings and infrastructure ...
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### What came first, Rice Crispy or “Snap,” “Crackle,” and “Pop”? [closed]

The fourth, fifth, and sixth derivatives of position are called "Snap" "Crackle" and "Pop". What came first, the rice crispy characters, or the physics units?
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### Calculate kinematics of body movement from the set of spatial coordinates

Short intro I have a set of 3D (x,y,z) spatial coordinates of arm movement obtained using motion capture system. The example set of such coordinates looks like this (rounded up): ...
### Why $F=ma$ and not $F=m\dot{a}$?
What would happen if instead of $F=m*d^2x/dt^2$, we had $F=m*d^3x/dt^3$ or higher? Intuitively, I have always seen a justification for $\sim 1/r^2$ forces as the "forces being divided equally over ...