All Questions
Tagged with kinematics acceleration
704 questions
2
votes
1
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606
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, $a ∈ [-A, A]$...
- 121
3
votes
4
answers
3k
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 ...
- 33
0
votes
0
answers
262
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 ...
- 121
0
votes
1
answer
1k
views
If the velocity of an object is decreasing at a constant rate, does it mean that it's a uniformly accelerated motion?
If the velocity is constantly decreasing from $u$ to $v$ so is it uniformly accelerated motion?
3
votes
1
answer
1k
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Confusion in coordinate transformation of acceleration vector
Consider this notation for vectors:
$A_{cb}^{d}$ is the $A$ vector (velocity,acceleration, angular velocity or ...) of $b$ coordinate frame w.r.t. $c$ frame presented in $d$ frame axis.
I know when we ...
- 31
-1
votes
2
answers
179
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 ...
- 13
2
votes
3
answers
153
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 ...
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2
votes
3
answers
16k
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.&...
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 $8\; \rm m/s$. ...
- 735
0
votes
3
answers
335
views
Computing the $x$-$y$ position of a vehicle for constant acceleration
I want to very simplistically plot the $x$-$y$ position of a vehicle in 2D that can accelerate/brake and drive a constant speed while turning etc.
The basic equations for determining the position for ...
- 13
0
votes
3
answers
276
views
Why are the seat belts designed the way they did? [closed]
I understand the importance of seat belts in vehicles. Since our body is moving at the same speed as the car, there should be something holding us tight in our seat when we step on the brake. Most 3-...
- 3,494
0
votes
1
answer
421
views
Equation for four-acceleration
Wikipedia states that
$$ \begin{align} \mathbf{A} =\frac{d\mathbf{U}}{d\tau}
&= \left(\gamma_u\dot\gamma_u c,\gamma_u^2\mathbf a+\gamma_u\dot\gamma_u\mathbf u\right) \\
&= \left(\gamma_u^4\...
- 196
0
votes
3
answers
471
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 ...
0
votes
1
answer
972
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 ...
- 13
0
votes
2
answers
283
views
Is radial velocity parallel to radius of curvature or the position vector?
I'm a bit confused regarding the directions of velocities and acceleration in curvilinear motion. Assume a curvilinear motion, which is not circular. I know that tangential component of velocity and ...
- 337
0
votes
2
answers
234
views
How to find velocity and acceleration at a point given acceleration in terms of position [closed]
A particle moves along a horizontal straight line with an acceleration $𝑎=6 𝑠^{1/3} m/s^{2}$. When $t = 2 s$, its displacement $S = 27 m$ and its velocity $v = 27 m/s$. Calculate the velocity and ...
- 242
-2
votes
2
answers
53
views
Projection of ball. find initial velocity [closed]
A cannonball is fired at an angle of 33 degree relative to the horizontal as shown in the figure bellow.
It is 1930 meters in the horizontal direction from the point of launch to the point where the ...
-1
votes
1
answer
74
views
Trying to solve second equation of motion without substituting $v=(at+v_i)$ [closed]
The derivation of $s = s_0 + v_0t + ½at^2$ starts with $v = dx/dt$, which is rewritten as $v dt = dx$ and then $v$ is replaced with $at+v_i$. Then it is integrated.
Why is this substitution done, ...
- 1
-1
votes
2
answers
380
views
When do you add or subtract vectors? [closed]
so I have a question here:
An airplane travelling initially at 240 m/s[28° s of e], takes 35 s to change its velocity to 220 m/s[28°e of s]. what is the average acceleration over this time interval?
...
- 19
0
votes
0
answers
13
views
If the velocity of an object is zero, does it mean that the acceleration is zero? [duplicate]
I am reading a book and the author threw the question of the title for us to reflect. After he gave us some example to state that if the velocity of an object is zero it doesn't mean that the ...
- 141
0
votes
2
answers
246
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 ...
- 119
-1
votes
1
answer
1k
views
Uncertainty in acceleration given two velocities and two times
I took a cart on a track and measured the velocity at two positions and the amount of time it took to get from gate 1 to gate 2. I have solved for the uncertainty of the velocity (was specifically ...
1
vote
0
answers
45
views
Is there an upper bound on acceleration? [duplicate]
We know from the Theory of Relativity that there is an upper bound on velocity, namely the speed of light $c=2.99792458\cdot 10^8\frac{m}{s}$. Is there an analogous upper bound on acceleration? I don'...
- 488
0
votes
1
answer
469
views
Would the jerk of this rocket be constant?
I was working on this interesting problem I came up with for a couple hours and got stuck - decided to ask here.
A rocketship with is accelerating upward with constant thrust. Ignoring air resistance ...
- 103
5
votes
5
answers
749
views
In circular motion, is the trajectory a resultant path of the given velocity and the velocity due to the centripetal acceleration?
For circular motion to happen we need a centripetal force or acceleration i.e. a force perpendicular to the direction of motion at all instants. So without any perpendicular component of force ...
- 8,476
0
votes
3
answers
1k
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What is the difference between non-uniform velocity and acceleration?
So I know non-uniform velocity as, "Non-uniform velocity is when an object covers unequal distance in equal interval of time in a particular direction or covers equal distance in equal interval ...
- 1
0
votes
5
answers
654
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Solution for quadratic formula in physics problems [duplicate]
I’ve solved a physics problem about acceleration with the quadratic formula and I don’t understand the solutions.
There is two vehicles A and B. A is before B of 50 meters. The velocity of A is 20 $ms^...
2
votes
1
answer
202
views
Why can gravitational acceleration not be detected by experiments
I was doing research into how $G$ forces are calculated, and I was told that they show all acceleration that can be "sensed" by humans (i.e. all non-gravitational acceleration).
This ...
- 318
1
vote
2
answers
50
views
Linearity in acceleration in kinematics (Intro to Physics)
I am a student in an Introduction to Physics class, and I have the following question which I am confused about, and how two parts of the answers relate to each other. (We are doing 1d kinematics)
A ...
user275102
1
vote
3
answers
53
views
Intersection point from acceleration [closed]
Two objects facing each other over a distance of 88m start moving from rest at an acceleration of 0.3m/s^2 and 0.2m/s^2 respectively, after how long do they intersect?
I've tried everything to find ...
- 11
2
votes
3
answers
253
views
How do we define $G$s?
I am going to explain what I think I know and how that leads up to my question - please correct any false claims I make or conclusions I draw.
I initially thought that $G$s were defined purely by ...
- 318
0
votes
1
answer
352
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 ...
3
votes
0
answers
398
views
Possible to convert accelerometer $x,y,z$ measurements into quaternion?
I have an inertial measurement unit (IMU) with an accelerometer that reports the acceleration (a) along the $x$, $y$ and $z$-axis in milli-$g$. I can get the Euler angles for roll ($\phi$) and pitch ($...
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0
votes
1
answer
125
views
Apply acceleration that is always opposite to the velocity
I have 2 functions for the $x$ and $y$ components of the velocity of an object ($z$ should always be $0$ in this case)
$$V_x(t)=v_{xi}+\int_0^ta_x(t')dt'$$
$$V_y(t)=v_{yi}+\int_0^t(-g+a_y(t'))dt'$$
...
1
vote
2
answers
217
views
Acceleration transformation in special relativity
I am having a hard time understanding the transformation of acceleration when it is not parallel to the instantaneous displacement of the particle, in particular the its dimension.
Suppose a particle ...
- 193
-6
votes
4
answers
676
views
Motion in a straight line [duplicate]
Velocity and acceleration are directly proportional to each other but in the case of throwing a ball up , at the top velocity is zero but acceleration is there. why?
4
votes
2
answers
312
views
Force and Accleration
It's just a basic question I had when I was studying physics years back,
So acceleration have two equations
$$a=\frac{F}{m}$$
and
$$a=\frac{\text{d}v}{\text{d}t}$$
So by the first equation, if I'm ...
- 171
2
votes
1
answer
269
views
How to read double integrator equations?
From what I understand, double integrator is a model where some entity can move according to some speed, which depends on the acceleration force exerted on the entity.
If someone would ask me to ...
- 143
0
votes
5
answers
655
views
Why are there seemingly two conflicting equations for velocity from acceleration?
In high school physics, I was taught three different equations related to accelerated motion:
$v=at$
$x=\frac{1}{2}at^2$
$x=vt$
As one does in high school physics, I pretty much just mindlessly used ...
-2
votes
3
answers
691
views
Is this the reason why acceleration isn't change in velocity per unit distance?
I believe that the reason acceleration isn't measured as change in per unit distance but instead is measured as change in per unit time is because of the following reason :
Time is not geometrical. It ...
- 161
0
votes
7
answers
404
views
Vertical motion of an object
We define acceleration as $-9.8\frac{m}{s^2}$ for an object that is thrown upwards due to gravity. My question is when the object reaches maximum height at the point where it is about to turn around ...
- 23
0
votes
1
answer
3k
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How to determine the correct time using quadratic functions if there are multiple "correct" roots exist in a 3D system? [closed]
Time can be calculated from a modified kinematics quadratic formula using the initial velocity, displacement, and acceleration. However, the acceleration vector isn't limited to 1 axis.
When applying ...
- 101
1
vote
1
answer
21
views
Help with finding speed and coordinates [closed]
Can you please help me with this I'm stuck?
A particle starts from rest at $t=0$ at the origin and moves in the XY plane with a constant acceleration of $a=( 2i+4j)\ \mathrm{m/sec^2}$
After a time of $...
-2
votes
2
answers
2k
views
Are uniform acceleration and uniform motion the same? [closed]
Any answers are appreciated, thanks. :D
1
vote
2
answers
849
views
Force creates the motion or Motion creates the force?
Motion Creates Force ?:
When you move your hand (to push a box for example), it creates a force.
When electron moves through a wire it creates electrical force.
Or Force Creates Motion ?:
Gravity ...
- 113
1
vote
2
answers
167
views
Velocity and acceleration in special relativity
I would like to compute what the constant acceleration trajectories are in the Minkowski spacetime $(t, x)$ with $d\tau^2 = dt^2 - dx^2$. So given some trajectory $x(t)$ I know the velocity vector is ...
- 592
0
votes
2
answers
4k
views
What kind of motion does a quadratic position time graph represent? [closed]
When I make a function to represent an object's position at intervals of two seconds, and it is parabolic, for example $f(x)=\dfrac{5x^2}{2}$ with the following points:
$ \text{seconds} \ \ \text{...
-2
votes
6
answers
2k
views
How is acceleration calculated when only the direction of velocity changes and the magnitude remains the same? [duplicate]
How is acceleration calculated when only the direction changes and the magnitude remains the same?
Guys, I know that my previous examples didn’t make sense and I’m sorry because I’m totally new to ...
- 23
0
votes
0
answers
62
views
Why don't we use vector sign for quantities in 1D motion? [duplicate]
My school textbook says that we don't need to use unit vectors (i ,j,k) to represent the direction of vectors in 1D motion as + and - sign indicate direction. But that is creating a lot of confusion ...
- 21
0
votes
3
answers
232
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 ...
- 71