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2 votes
1 answer
538 views

How to determine the minimum "Arrival Distance" given a maximum velocity, acceleration and jerk along with an initial velocity and acceleration?

Problem Given the following: $A$ - maximum acceleration. $J$ - constant jerk (the rate of change of acceleration). $v$ - initial velocity. $a$ - initial acceleration (where, in practice, $a ∈ [-A, A]$...
mindTree's user avatar
  • 121
3 votes
4 answers
2k views

If displacement is 0, does that mean initial velocity equals final velocity?

For instance, one of the kinematic equations is : $$v_f^2 = v_i^2 + 2ad$$ where $v_f$ is final velocity, $v_i$ is initial velocity, $a$ is acceleration, and $d$ is displacement. Say for instance a guy ...
Pro Grammar's user avatar
0 votes
0 answers
227 views

How to determine the distance travelled before a maximum acceleration is reached given a constant jerk?

Problem Given: An initial velocity and acceleration of 0. A maximum acceleration $A$ A constant jerk $J$ How might one determine the distance $D$ traversed before the maximum acceleration $A$ is ...
mindTree's user avatar
  • 121
-1 votes
2 answers
167 views

Problem in instantaneous acceleration and instantaneous velocity

Recently i came accross a problem that said An object is dropped straight down from helicopter the object falls faster and faster but its acceleration decreases over time becoz of air resistance. the ...
rahul amare's user avatar
2 votes
3 answers
147 views

Query regarding instantaneous velocity and instantaneous acceleration

Suppose an object's velocity is $5 \ \text{m/s}$ at $t = 1$ seconds and $8 \ \text{m/sec}$ at $t = 2$ seconds then the acceleration here is $3 \ \text{m/sec$^2$}$ i.e at $t = 1$ seconds the ...
rahul amare's user avatar
1 vote
3 answers
12k views

Does the SUVAT equations of motion (Kinematics) come from some differential equation?

Wikipedia says about the equations of motion that; "If the dynamics of a system is known, the equations are the solutions for the differential equations describing the motion of the dynamics.&...
Shadman Sakib's user avatar
3 votes
3 answers
357 views

Calculating displacement from acceleration (intuitively) [closed]

If I say acceleration of car is constant at $4\; \rm m/s^2$. Then isn’t it that it covers $4\; \rm m$ in $1\; \rm s$ with velocity $4\; \rm m/s$. Then in $2\; \rm s$, the velocity is $8\; \rm m/s$. ...
Srijan's user avatar
  • 725
0 votes
3 answers
421 views

What is correct definition of tangential acceleration?

Is tangential acceleration the rate of change of magnitude of velocity OR, Is it simply the rate of change of velocity? I am asking this because I am sort of confused, because there is no tangential ...
CREATIVITY Unleashed's user avatar
0 votes
3 answers
1k views

How does gradient give $g$?

How is $$g=-\nabla V$$ where $V$ is gravitational potential and $g$ is acceleration due to gravity. I am new to calculus.
protectgoodlivingbeingask's user avatar
0 votes
1 answer
859 views

Convert Acceleration-Time Graph to Velocity Time Graph [closed]

I have a set of 40 readings that make up 2 seconds of simple harmonic motion of an extension spring and I would like to use these readings to come up with a graph and if possible a function that ...
unknownUser's user avatar
0 votes
2 answers
238 views

Why are these SUVAT equations true?

\begin{align} v&=u+at\\ s&=ut+\frac{1}{2}at^2\\ v^2&=u^2+2as\\ s&=\frac{(v+u)t}{2} \end{align} I have just started with learning acceleration in school and I don't really understand ...
randomlad's user avatar
  • 119
0 votes
1 answer
141 views

Differential Equation & MacLaurin Series for Newton’s Second Law

I am currently working with a differential equation, where I think I need to take the derivative of $ma$ (corrected as per comment). I am trying to write $F = ma$ as a MacLaurin series and eventually ...
Yelena's user avatar
  • 151
0 votes
1 answer
335 views

Acceleration function of position and time

I have an acceleration function in python with position and time parameters and returns the acceleration value. I need the end velocity at a position ,start velocity is zero. how to calculate this ...
MohammadAli Zeraatkar's user avatar
0 votes
3 answers
230 views

Are acceleration and velocity simultaneous? [closed]

I would think yes because, if a rope tied to a swinging rock breaks, the rock flies off in the direction that is perpendicular to the direction of the last instant of the acceleration. The ...
Nectac's user avatar
  • 71
0 votes
2 answers
85 views

Kinematic displacement: why not represent higher order rates of change?

I understand that the equation for kinematic displacement is: $x = v_{0x}t+\frac{1}{2}a_xt^2$ Perhaps my understanding is naive, but it seems like this leaves out higher order rates of change. Why ...
devinbost's user avatar
  • 111
1 vote
2 answers
2k views

Acceleration as a function of position and time

I know if you have an acceleration as a function of $t$, $a(t)$, to find the velocity you simply integrate $a(t)$ with respect to $t$. Moreover, if the acceleration was a function of position, $a(x)$, ...
Tim CP's user avatar
  • 33
1 vote
2 answers
546 views

In the equation: $a = dv/dt$ , is $dt$ the time taken to achieve that instantaneous acceleration?

If you solve for $dt$ from $a = \frac{dv}{dt}$ , is it the time taken to to achieved that instantaneous acceleration? $a$ : acceleration $v$ : velocity $t$ : time
Curious 's user avatar
9 votes
4 answers
2k views

Can I find the acceleration or velocity when my displacement-time graph is discontinuous?

Today, I encountered the problem where I was asked to find the velocity and acceleration from displacement-time graph but the displacement-time graph was discontinuous. So I am unable to find the ...
Roger Michealson's user avatar
0 votes
1 answer
276 views

Trying to prove that the expression for the radial component of the acceleration is equal to $\mathbf v\cdot \mathbf v/r$

I am trying to prove that the normal component of acceleration of a particle undergoing a curvilinear motion is equal to $\mathbf v\cdot \mathbf v/r$. Here $\mathbf v$ is the velocity of the particle ...
It's probable's user avatar
12 votes
4 answers
3k views

Integrating acceleration - wrong choice of bounds in textbooks?

I've noticed in my physics textbook (and in a lot of other popular sources), that the process of integrating non-constant acceleration to get to a velocity formula, the integrating bounds imposed on ...
Ius Klesar's user avatar
11 votes
4 answers
3k views

When the direction of a movement changes, is the object at rest at some time?

The question I asked was disputed amongst XVIIe century physicists (at least before the invention of calculus). Reference: Spinoza, Principles of Descartes' philosophy ( Part II: Descartes' Physics, ...
user avatar
5 votes
2 answers
2k views

How does instantaneous velocity or acceleration have any other numerical value than 0? [duplicate]

Instantaneous velocity is defined as the limit of average velocity as the time interval ∆t becomes infinitesimally small. Average velocity is defined as the change in position divided by the time ...
McFluff's user avatar
  • 163
6 votes
6 answers
1k views

Question about derivation of kinematics equations

Apologies if this has been asked before, but I browsed the sub and couldn't find something specific. I understand the derivation for one of the equations as follows: \begin{gather} \frac{dv}{dt} = a ...
ChemSniper's user avatar
1 vote
5 answers
152 views

Equation of distance and time

How is this equation derived? $$r = r_0 + ut + at²/2$$ where $r_0$ is the initial position of particle and $r$ is the position of the particle after all the motion it has undergone, $a$ and $t$ ...
user231094's user avatar
2 votes
5 answers
1k views

Acceleration and motion can be in different direction?

I'm not getting what acceleration concept is and how it relates to motion and how motion and acceleration can be in different direction? And what's behind the concept of negative and positive ...
Asta's user avatar
  • 31
0 votes
2 answers
42 views

Intuition of Distance covered when accelerating [duplicate]

When you're moving at $5$ m/s for $1$ second, you have traveled $5$ m. When you're moving at $5$ m/s (initial velocity) and you accelerate $2$ m/s for $1$ second, you have traveled $5$ m + $1$ m (...
austingae's user avatar
  • 163
0 votes
0 answers
372 views

Why don't we define time derivative of acceleration? [duplicate]

When we started the study of kinematics we defined position and its change with respect to time. After that we defined time derivative of velocity which gave us acceleration. These 3 concepts really ...
Shreyansh Pathak's user avatar
0 votes
1 answer
55 views

Change of variable in function

Suppose I have a function $h(\theta)$ measuring the height of a piston, with $\theta = \omega t$. I would like to know the vertical acceleration of this piston as $\omega$ changes at the point $\theta ...
Mikkel Rev's user avatar
  • 1,356
0 votes
0 answers
94 views

Acceleration as the second derivative of displacement function

Let $x$ be displacement as a function of time $t$ and some other physical quantity $k$ such that $ x = f(t,k) $ Now, 1) Will the acceleration $a$ be $\frac{\partial^2 x}{\partial t^2}$ or $\frac{d^...
StaticESC's user avatar
0 votes
1 answer
174 views

calculate the time elapsed for a robot to pass certain distance with a load [closed]

For a robotics project I wanted to find the optimal gear ratio for my robot to travel 10 meters. Unfortunately. the acceleration is nonconstant, and that proved to make my life much harder. I think I ...
Avalanche's user avatar
-1 votes
1 answer
272 views

Integration of Acceleration to Get Delta Velocity

How do you get delta velocity if you have times t1 and t2 and their velocities v1 and v2, but you only know their accelerations a1 and a2. If you integrate over accelerations a1 and a2, do you get a "...
tomihasa's user avatar
0 votes
1 answer
95 views

Acceleration Question

I'm really confused how we have a distance formula from acceleration. I understand acceleration is the change of velocity/time, however I don't understand how you can calculate a distance based on a ...
Mike 's user avatar
  • 71
0 votes
2 answers
990 views

Condition of acceleration when using $x=vt$

So my teacher told me that since $v = \delta x/ \delta t$, $\delta x = v • \delta t$ (naturally), and that is equal to the "area under the velocity-time graph", or displacement. This all makes sense ...
space's user avatar
  • 157
1 vote
2 answers
2k views

Why is there a $\frac{1}{2}$ in the kinematic equation? [duplicate]

In a few of the kinematic equations there is a $2$ or a $0.5$ coefficient. Why is this? For example the kinematic equation for distance is: $$\text{previous velocity} * \text{time} + \frac{1}{2} * \...
Philogy's user avatar
  • 115
2 votes
1 answer
3k views

Integrating an acceleration time graph gives you?

If I have a graph of Acceleration against time. Can I integrate this curve in order to find velocity and displacement?
Richard Woods's user avatar
0 votes
4 answers
659 views

Question about $a = v\ \mathrm dv/\mathrm dx$

Consider $\vec{v}$ Now differentiating this w.r.t time, $$\vec{a} = d/dt( \vec{v}) = \vec{v}(d\vec{v}/dx)$$ Now this multiplication of vectors obviously makes no sense. This along with the fact that ...
xasthor's user avatar
  • 1,096
-1 votes
1 answer
207 views

Is there any reason why acceleration should not be the first derivative of the absolute value of velocity? [closed]

I ask mainly because I am not familiar enough with newtonian mechanics and higher-level physics in general to know the repercussions of such a change, but on the simpler plane of existence, I have ...
Azorack's user avatar
11 votes
2 answers
3k views

Kinematic equation as infinite sum

I'm not sure exactly how to phrase this question, but here it goes: $v=\dfrac{dx}{dt}$ therefore $x=x_0+vt$ UNLESS there's an acceleration, in which case $a=\dfrac{dv}{dt}$ therefore $x=x_0+v_0t+\...
gen-ℤ ready to perish's user avatar
5 votes
2 answers
2k views

Why does acceleration need to be constant if integrating?

My teacher wrote the following: Constant Acceleration If acceleration is constant, then: $$\vec{v}(t) = \int_0^t \vec{a}(t')dt'\ + \vec{v_0}$$ and $$\vec{x}(t) = \int_0^t \vec{v}(t')dt'\ + \vec{...
rb612's user avatar
  • 1,177
4 votes
2 answers
2k views

Calculating Intensity/Strength of Vibration with 3DOF

I want to calculate the intensity/strength of vibration at a given location. I have measured the acceleration at this location, using an accelerometer. So my measures look for example like: ...
Robin's user avatar
  • 43
0 votes
4 answers
262 views

Explain $\Delta x = v_0t + \tfrac{1}{2}gt^2$ please? [duplicate]

$g = \Delta v/t$, so $\Delta v = gt$. $v = v_0 + \Delta v$, so $v = v_0 + gt$. So if $\Delta x = vt$, then $\Delta x$ should be $v_0t + gt$. Why the $\tfrac{1}{2}gt^2$? I'm really confused, so this ...
user3724492's user avatar
-1 votes
1 answer
1k views

Calculating Potential Energy

I'm familiar with the potential energy equation, but I'm concerned with the value of 'g' in it. I know that, at sea level, earth's gravitational acceleration is 9.81 m/s/s. So I know that within the ...
Jean Valjean's user avatar
0 votes
1 answer
74 views

Current Electricity

If $$ \frac{dQ}{dt} = I $$ and if an accelerated current produces E.M. waves (radiation), does that mean $d^2Q/dt^2$ (second derivative of a charge w.r.t. time) will give me the magnitude of the wave ...
Jay's user avatar
  • 3
2 votes
3 answers
1k views

Basic question about acceleration [duplicate]

Very basic question. Please show where I'm wrong in the following reasoning. The movement of an object in function of time could be described as $$ x(t) = v t + x_{i} $$ if velocity is constant. If ...
Alex T's user avatar
  • 129
24 votes
7 answers
12k views

Zero velocity, zero acceleration?

In one dimension, the acceleration of a particle can be written as: $$a = \frac{dv}{dt} = \frac{dv}{dx} \frac{dx}{dt} = v \frac{dv}{dx}$$ Does this equation imply that if: $$v = 0$$ Then, $$\...
7453rfg's user avatar
  • 383
2 votes
2 answers
15k views

Calculate displacement in position from knowing constant acceleration

I have recently started studying physics at school, and my teacher went over the following equation without explaining about it too much: $$s=\upsilon_{0}t+\frac{1}{2}a t^2 $$ I have wondered, why ...
rel-s's user avatar
  • 137
20 votes
5 answers
132k views

How to get distance when acceleration is not constant?

I have a background in calculus but don't really know anything about physics. Forgive me if this is a really basic question. The equation for distance of an accelerating object with constant ...
ben's user avatar
  • 1,517

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