All Questions
Tagged with rotational-kinematics acceleration
55
questions
-2
votes
2
answers
98
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Why does $\vec{a}=\vec{\omega}\times \vec{r}$ as well as the velocity does?
Today I came in class and in one of the problems the teacher used $\vec{a}=\vec{\omega}\times \vec{r}$ which made me very confused because I don't know where it comes from, it seems pulled out of thin ...
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1
vote
1
answer
159
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How to compute linear acceleration in 3D from change in roll, pitch and yaw angles?
We know that if a body is rotating only about $z$-axis along a circle of radius $R$ with an angular rate of $\omega$, then the acceleration of the body in 3D is $a = [0.0\ \ \omega^2R \ \ 0.0]$. Now ...
- 123
0
votes
1
answer
51
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Does a rotating body resist acceleration in a direction that is perpendicular to the direction of the rotation of the body?
I would like to know if a rotating body resists acceleration in a direction that is perpendicular to the direction of the rotation of the body.
Say for example there is a bicycle wheel with a tire on ...
- 478
2
votes
1
answer
69
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(Circular motion) Acceleration is given, so why asked for more? [closed]
The full question is below.
A car starts from rest and moves around a circular track of radius $32.0\,\text m$. Its speed increases at the constant rate of $0.500\,\text{m/s}^2$.
(a) What is the ...
- 21
0
votes
2
answers
328
views
Does a simple pendulum have some radial acceleration at its extreme positions where its speed becomes zero?
Suppose we have a simple pendulum swinging between two extreme positions. At the extreme position its speed becomes zero. As per this reason can I say that at extreme positions radial acceleration (v^...
- 1,357
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2
answers
277
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Is accelerated rolling with slipping possible?
I have a conceptual question regarding the following tasks. Two cylinders with different coefficients of friction are rolling down a inclined plane, thus accelerating. According to the task, due to ...
- 47
0
votes
2
answers
706
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What is the real difference between radial and tangential acceleration?
So in my physics coursebook there are two different kinds of derivation of $\frac{dv}{dt}$ of a particle rotating in a circle. Most of you will know these, they are what is called centripetal/radial ...
0
votes
1
answer
579
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I am very confused about net acceleration and angular acceleration in circular motion [closed]
I have seen in many places that angular acceleration can be zero but net acceleration can't be zero in circular motion. I want to know whose components are tangential and radial acceleration (net or ...
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0
votes
2
answers
51
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Can a particle make a turn in space without accelerating? Does the size of the turn it makes, make a difference?
Is it possible for a particle to have angular velocity but no angular acceleration? Even if the angular velocity does not change, does there always need to be a centripetal / centrifugal acceleration ...
user319855
0
votes
1
answer
731
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Angular acceleration related to a time dependent rotation matrix $R(t)$
Let the orientation of a coordinate frame $\{b\}$ w.r.t. a static coordinate frame $\{a\}$ be expressed by a rotation matrix $R_{ab}\in SO(3)$ whose columns represent the coordinates of the unitary ...
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2
votes
1
answer
39
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Finding Average Acceleration with only given angle [closed]
A car enters a curve in the road with a speed of 32 m/s and emerges from this curve 4 s later with the same speed. However, the direction of the velocity changes by 150 degrees during this time.
What ...
- 21
1
vote
2
answers
99
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Use of net acceleration in circular motion
We know there are two types of accelaration in circular motion, one is centripetal acceleration and the other one is tangential acceleration. The resultant of these two is the net acceleration $a$. ...
- 1,179
4
votes
4
answers
427
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Centripetal force equation doubt
In a centrifuge, $a_c$ should be constant. If $m$ increases, the $r$ will increase in order to maintain a constant $a_c$.
Constant centrieptal acceleration is given by
$a_c={ v^2 \over r}$
and $a_c = ...
1
vote
5
answers
583
views
Confusion about acceleration in rotating without slipping
We know that if there is a flat surface with friction, a ball rolling without slipping will conserve its energy, as friction does no work on the ball.
$$\Delta E = 0 $$
Because kinetic energy is ...
1
vote
3
answers
186
views
Definition of torque in the (possibly accelerating) centre of mass frame
My lecture note states that the torque in the centre of mass frame ($O^*$) of a rigid body is: $$\bf{G^*}=\sum \bf{r^* \times F}$$
where $\bf{F}$ denotes the real force that is producing the torque
...
- 1,047
-1
votes
2
answers
724
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In rotational motion, why $a = rα$?
The formula of torque is given by $$τ= F*r = Iα,$$ while solving some questions I came across a question of rotating pulley where these two formulas were equated to find value of $α$. How $a=rα$? a ...
13
votes
12
answers
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Why is acceleration directed inward when an object rotates in a circle?
Somebody (in a video about physics) said that acceleration goes in if you would rotate a ball on a rope around yourself.
The other man (ex Navy SEAL, on YouTube too) said that obviously it goes out, ...
- 349
0
votes
3
answers
820
views
Condition for pure translational motion
Q:If we know that the acceleration vectors of all points of the rigid body are equal to each other at all points of time, can we conclude that the body is undergoing pure translational motion?
I ...
- 1
1
vote
1
answer
104
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Wheel slips and weight
With rainy season starting, I have been thinking about traction and have a question:
Question: If two identical vehicles, one of mass $m$ and the other of mass $2m$ are starting from rest with equal ...
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2
votes
1
answer
125
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About the water surface in a accelerated cylinder
After I woke up this morning while sitting at our table I looked at a plastic bottle of cola lying on the floor. Please, don't think it's a mess out here. It just lay there. I put it nicely back on ...
6
votes
5
answers
1k
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Finding accelerations using Instantaneous axis of rotation
Disclaimer: I present a question which is homework-like, However it is simply to demonstrate an example. I only wish to clarify one thing, that is the validity of the IAR in determining the ...
- 1,295
5
votes
3
answers
2k
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Does tangential acceleration change with radius? [closed]
Do tangential velocity and tangential acceleration change with radius (change of radius on the same object)?
For example consider a spinning disk. Does the equation $$a_t = \alpha R$$ (where $a_t$ ...
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vote
3
answers
595
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Angular Acceleration v. Centripetal Acceleration
What is the difference between angular acceleration and centripetal acceleration? Don't they both apply to circular motion?
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vote
1
answer
371
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Acceleration of a Point on the Edge on a Rolling Cylinder
Consider a cylinder with radius $R$ rolling without slipping to the right. The center of mass is rolling with a velocity of $v$. Consider the left most point, $p$, on the cylinder. What is the ...
0
votes
1
answer
446
views
Calculating acceleration of an object using $x$, $y$ and $z$ coordinates [closed]
I have x, y and z coordinates for a test I had carried out for a tool. I had an accelerometer installed on the tool and I used two types of motion to move the tool, rotation and translation. Right now ...
0
votes
0
answers
65
views
Does acceleration of the rim mean just tangential or both tangential and centripetal acceleration?
On my physics homework, the problem specifies that the acceleration of the rim of a flywheel can't exceed 100g. Does this mean that the tangential acceleration only, or the sum of the tangential and ...
- 1
2
votes
3
answers
113
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What is wrong with this reasoning?
Suppose a particle is rotating about a point at a distance $r$, then since $r$ is constant $\frac{\text dr}{\text dt}=0$ so the component of velocity along the position vector should be zero. ...
- 88
1
vote
2
answers
3k
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Find the time when tangential acceleration is equal to radial acceleration [closed]
A particle begins to move along a circular path of radius R with a constant magnitude tangential acceleration of $a_t$. After time $t$ it's the centripetal acceleration is equal in magnitude to ...
- 132
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votes
2
answers
235
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Intuition for formula of tangential component of acceleration in general curvillinear motion
In certain problems of plane motion, the position of the particle P is
defined by its polar coordinates $r$ and $\theta$. It is then convenient to resolve the velocity and acceleration of the particle ...
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votes
1
answer
133
views
When a body completes one revolution around a circular path will its acceleration be 0?
When a body is moving in a circular motion the acceleration keeps changing, will it be zero when it comes back to the same point it started from(will the average acceleration be 0?)
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0
votes
2
answers
2k
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Torque, Angular Acceleration and Linear Acceleration
We know that we torque is applied, it cause an angular acceleration in the rotating body similar to what a force does to a body moving on a straight line.
But my question is, Does Torque affect the ...
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2
answers
2k
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Can acceleration at a point be non-zero if angular velocity is zero?
I have just started studying rotational kinematics.
0
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1
answer
137
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Why is acceleration in the rotating system zero?
Given a circular body that rotates around itself and there is a band(or iron line) that connects between the Cartesian coordinate system and its Perimeter, on the band, there is an ant that walking ...
- 101
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1
answer
87
views
Can we measure little $g$ in this way?
If a cup of water (known mass) is whirled round at the end of a string, and we look for the exact angular velocity which makes water remain in the cup, is it possible, by knowing the force equilibrium,...
user153036
1
vote
1
answer
112
views
What will be the trajectory of the given motion [closed]
If it is given that component of acceleration perpendicular to the velocity of a body has a constant, non-zero magnitude, how can we mathematically prove that the trajectory of the body will be ...
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2
votes
1
answer
952
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Kinematics for Non-Uniform Circular Motion
I'm trying to understand how kinematics for non-uniform circular motion. I know that you can represent the net acceleration of an object in non-uniform circular motion with the following equation:
$$...
1
vote
3
answers
3k
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Why normal acceleration doesn't bring a change in speed?
Suppose There's a particle of mass m moving with speed $v_{0}$, at certain moment a force starts acting on it (centripetal force) and it start uniform circular motion
Now every other reference states ...
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2
votes
1
answer
2k
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How will "a block on a turntable" move when the turntable move very fast?
If there is a block that is placed at the rim of a turntable, and we start rotating this turntable, I know that while the turntable is rotating, a centripetal force is acting on the block. This force ...
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1
vote
1
answer
120
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Which acceleration to use - Coriolis?
In this diagram, water is being ejected from a sprinkler, rotating at speed $\dot\theta = 2 rad/s$ and angular acceleration $\ddot\theta = 3 rad/s^2$ .
Water is flowing the the sprinkler at $3m/s$. In ...
- 13
10
votes
4
answers
46k
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What is the relation between angular and linear acceleration?
I am wondering, when solving rigid body exercises, how can I express the relationship between linear and angular acceleration for a general case? E.g. what would be the linear acceleration in function ...
- 309
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vote
3
answers
4k
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Proof of Centripetal Acceleration Angle $\theta$ is the same?
The book I am reading shows a proof of centripetal acceleration.
It proceeds to say that the linear velocity is always at a tangent to the radius, so the angle between $V_A$ and $V_B$ is also $\theta$...
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0
votes
5
answers
16k
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tangential acceleration for uniform circular motion
I understand that circular motion is defined by 2 components of acceleration, one tangential and one radial and their resultant is what causes circular motion.
I am confused though as to why it is ...
- 137
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votes
2
answers
542
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Noninertial frame of reference
For a car that is accelerating linearly, the non-inertial frame of reference is the driver in the car where from his reference frame, the car is stationary. It is so called stationary because the non-...
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3
votes
5
answers
20k
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Radius of centripetal acceleration
Suppose you are moving in circle of radius $r$. So there should be centripetal acceleration towards the center. Now you want to decrease the radius of the circle, so someone should apply more ...
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-1
votes
1
answer
3k
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Why is angular acceleration of a pendulum always negative?
I was trying to derive using the Lagrangian the equations of motion of a simple pendulum under the influence of gravity. Eventually, I was brought to this conclusion:
$$\alpha = -(g\sinθ)/l$$ where $\...
- 182
3
votes
3
answers
1k
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instantaneous velocity center
The instant center of rotation, also called the instantaneous velocity center is the point fixed to a body undergoing planar movement that has zero velocity at a particular instant of time. For ...
- 4,377
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vote
3
answers
3k
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Why the similarity in the Equations of Motion for Rotational and Rectilinear Motion?
These are the equations of motion given constant acceleration, for first rectilinear and then rotational motion.
Rectilinear Motion:
Rotational Motion:
While the variables have changed, and the ...
- 283
21
votes
8
answers
112k
views
A simple derivation of the Centripetal Acceleration Formula?
Could someone show me a simple and intuitive derivation of the Centripetal Acceleration Formula $a=v^2/r$, preferably one that does not involve calculus or advanced trigonometry?
- 373
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votes
2
answers
733
views
How to treat an exercise about the rotational acceleration during a throw?
Because I am studying on my own, I don't have anyone to talk to about this when I don't understand, and I was wondering if someone could help me with a concept in rotational kinematics:
At the ...
- 101
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vote
1
answer
2k
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How to model a very simple spinning wheel
First off, I'm not a physics person, just a lowly software engineer with below average math skills. What I've written is a simple animation of a spinning wheel using C++/GTK/Cairo. It allows the user ...
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