The time derivative of angular position used when studying rotating objects or systems.

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3answers
57 views

A ball moves in the radial groove of a rotating disk [on hold]

As shown in the figure above, a ball can fit perfectly and move freely in the radial groove of a disk. There is no friction in the groove. We do not consider gravity here (or think the disk surface ...
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1answer
12 views

How to calculate the “angular braking distance” when you know the following values?

I have to calculate the arc length in radians that a circle spinning at speed will travel when it decelerates to $0$. I have the initial angular velocity in rad/s, the radius in meters, the mass in ...
2
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1answer
103 views

Kinematics of Euler angles relative to a rotating frame

I have a rotating body $B$ and a rotating frame $F$ whose orientations are described by the quaternions $q_B$ and $q_F$ respectively. I also have the angular velocity vectors $\omega_B$ and ...
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1answer
39 views

How much does air resistance affect the angular velocity of a golf ball?

I'm modeling the flight trajectory of a golf ball, and using angular velocity to calculate the Magnus force. Currently, I'm assuming angular velocity to be fixed throughout the ball's flight. How ...
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5answers
174 views

Why does solving $\mu mg = m \frac{v^2}{r}$ give the *max* possible velocity?

So here is the standard problem setup of a car turning on an unbanked road: A 1000 kg car is going around a curve with radius 30 meters. If the coefficient of friction between the car's tires ...
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2answers
95 views

Intuitive explanation for why centripetal acceleration is $\frac{v^2}{r}$

There are several ways to write centripetal acceleration $$\frac{v^2}{r} = \omega^2 r = v \omega$$ Are there intuitive explanations for any of these three forms? For instance, I can sort of explain ...
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1answer
32 views

Moving objects along a radius

I'm working on a project involving a Roomba which I'd like to move precisely from coordinate to coordinate. To move the Roomba manually you need to give it a velocity between -500 to 500mm/s and a ...
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0answers
27 views

Need clarification for Relation between angular momentum and centripetal force

I've recently started studying angular momentum, so, as far as I understand, angular momentum is conserved as long as any form of centripetal force can be maintained in the new system or otherwise it ...
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0answers
22 views

Can't we assign any other direction for instantaneous angular velocity except along the axis of rotation? [duplicate]

We specify the direction of instantaneous angular velocity using the right hand thumb rule. I just want to know that is it just a matter of convention or we don't have any other direction for it to be ...
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2answers
100 views

In which direction does mud fly off a moving bike's tire & why?

If a bike moves through a muddy area, mud gets on its tires. Then the mud flies off from the tires. Which forces are acting on it? In which direction does it fly off? On my physics test, I wrote ...
3
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1answer
47 views

Why do you seem to go faster as you hug a turn?

I was driving to work this morning when this question occurred to me. I was going up a clover-leaf entrance ramp to the highway. The person in front of me was lazily floating the outside of the curve, ...
2
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1answer
82 views

If $\omega = \frac{v}{r}$, why do we need torque?

If $\omega = \frac{v}{r}$, then why do we need torque and angular acceleration? The velocity v can be found just by Newton's second law of motion $F = ma => a = F/m$ and $v = v_0 + at$ . Then we ...
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1answer
36 views

Force responsible for increasing a spiraling object's tangential velocity

Suppose we have a small mass attached to a string that has been fed through a hole in the friction-less table on which the mass is rotating. Pulling the string downwards thus decreases the radius of ...
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1answer
65 views

Movement and Rotation of a Inverted-Pendulum-like Object with External Forces

I'm struggling to model the movement of a complex object based on an external force. Let's start with a simple example of what I'm looking for. We have a block $b$ of mass $M_b$, moving ...
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1answer
109 views

Calculating the charge of weights on a rod based on it's movement in an electric field

I've got a problem from my physics course which I am a little stuck on. A dumbell consisting of two identical masses m=5.8 kg attached to the ends of a thin (massless) rod of length a=0.4 m that ...
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0answers
31 views

Acceleration of an oscillating object in a frame of reference that is itself rotating!

I have been reading a paper and due to my limited knowledge of Physics, I can't move ahead. Sorry I do not know latex so, I will snip the paper and paste it here. So here goes it..... I think ...
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1answer
42 views

Angular velocity in central force field

For motion in a central force field consider a rotating reference frame, which is characterized by the Euler angles $\alpha$, $\beta$, $\gamma$ associated with the rotation of the frame of Cartesian ...
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2answers
136 views

How many hours will be in a day if the radius of Earth increases by 70 m?

I am little confused about the linear momentum and angular momentum, will the linear momentum of earth change due to changing of its radius or it will stay as it was and i know that the moment of ...
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0answers
12 views

Good reference on angular motion especially on linear and angular velocity? [duplicate]

I am currently using a book called "Classical Mechanics" by Goldstein, which is a very good text and has amazing introdution to Lagrangian mechanics. Unfortunately not too much is said about angular ...
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1answer
78 views

What causes angular and linear deceleration in a sliding and rotating ring?

I was solving an AP Physics problem involving a ring sliding and rotating over a frictional surface. When I started to think about why the ring eventually comes to a stop I started to become confused. ...
3
votes
3answers
72 views

Why is acceleration significant to generating power in racket sports?

I'm reading a paper on badminton stroke power (see Figure 4 on page 8). It says: For most of the trials the racket head reached peak speed just at the time of impact. The racket head showed ...
5
votes
3answers
671 views

How can I relate linear and angular motion using a single formula?

I want to relate linear and angular motion using a single formula. Assume I have a 10m rod, and I apply a force of 5N on it, 2.5m away from the axis of rotation for 1s. How can I determine the ...
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1answer
160 views

Equivalency of conditions involving angular momentum of a rolling ball hitting a wall

(59th Polish Olympiad in Physics) A ball of mass $m$, radius $r$ and a moment of inertia $I = \frac 25 mr^2$ is rolling on the floor without sliding with the linear velocity $v_0$. It hit the wall ...
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1answer
51 views

Angular velocity formula for a particle?

I know that when the motion of a particle is circular about the origin then: $$\vec v=\vec \omega \times \vec r$$ But that this does not hold for any motion with a radial as well as tangential ...
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1answer
85 views

Representation Of Linear Velocity as Cross Product

Why is linear velocity represented as cross product of angular velocity of the particle and its position vector? Why not vice versa? (Consider rigid body rotation)
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2answers
159 views

Need help with relationship between angular momentum, linear and angular velocity

I am in an introduction to engineering physics course and just trying to see if my understanding of angular motion is correct or if I have the wrong idea. So as I understand it, angular velocity is ...
3
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4answers
919 views

Puzzling : Relative motion of two points on a rotating disc

Consider two points on a radial line for a rotating disc. One point, $A$, is at the circumference and the other, $B$, is at distance $R/2$ from disc's centre. Relative velocity of $B$ w.r.t. $A$ ...
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0answers
68 views

why Angular Frequency is useful in comparison with spatial frequency in video?

what is difference between angular frequency and spatial frequency when we are talking about eye perceiving in a video. In many texts about video (for example Yao Wang's Video Processing and ...
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2answers
168 views

Instant centre of rotation for two connected gears

The two gears are have the angular velocities $\omega_1$ and $\omega_2$ respectively with respect to $Oxyz$. The task is to determine the angular velocity $\boldsymbol{\omega}$ of the arm ...
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1answer
133 views

If a car moves at a certain speed, how fast is its wheel going?

Say in a given instance a car moves with speed $v$ and consider any wheel of the car. How fast is it going? Is it the case that the center of the wheel moves at the same speed as the car i.e. $v$? Why ...
0
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2answers
141 views

When does the 'standard' angular velocity formula not hold?

I have read that the formula for angular velocity: $$\dot {\vec r}=\vec \omega \times\vec r \tag{1}$$ does not hold in some situations, but the book does not specify what situation so please could you ...
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1answer
155 views

Magnitude of the average velocity vector (not the average speed)

Thank you ahead of time for taking to look at this. For this following problem we were given an answer however I am almost positive the given answer is wrong. It doesn't even make sense. So here is ...
2
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1answer
77 views

components of angular velocity?

Let $\vec \omega = (\omega_1, \omega_2, \omega_3)$ be the angular velocity of a rigid body with respect to the body frame, where the body frame is right-handed orthonormal. I have gathered 2 ...
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1answer
50 views

Is the distance involved in calculating angular momentum to an axis or a point?

I'm a high school student.I still don't really understand angular momentum and moment of inertia. I know the moment of inertia of a point mass is defined as $mr^2$. For any other shape, we integrate ...
3
votes
3answers
116 views

Uniqueness of the angular velocity

Let us consider the most general motion of a rigid body. Two arbitrary points of the body, $i$ and $j$ must not change their distance $d_{ij}$ during motion. Therefore,$$(\vec{r}_j - \vec{r}_i)^2 = ...
0
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1answer
171 views

Angular Velocity at different points on a rigid body [duplicate]

Why is it that Angular Velocity of a body about any point the same ? Eg: If a rod hinged at one end rotates with an angular velocity W the angular velocity about its center is also W. Also is it ...
2
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0answers
105 views

The relativistic effects of angular velocity

Imagine I have a circular disk in a vacuum. I apply a constant force, so a constant torque on the disk. My first question is: does this disk have a angular velocity speed limit? I believe it does, ...
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1answer
66 views

Angular velocity of disc from induced motion

I came across a question regarding linear momentum $L$ and it's conservation, however I tried and got confused. It reads: A $40kg$ girl stands on the very edge of a rotating disc of mass $50kg$ and ...
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0answers
43 views

Describing the motion of a point-mass [closed]

Consider a point-mass moving around a fixed point on a circle with radius $r$ with constant angular velocity $\omega$. At a certain moment of time, the connection is removed, and the point-mass flies ...
0
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1answer
56 views

Are velocity and accelerate smooth quantities?

My thinking: acceleration corresponds to a force which is instantaneous, so the acceleration of a rigid body can be rather spiky (non-smooth) velocity (angular velocity) describes the ratio of ...
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3answers
427 views

Minimum angular velocity for circular motion (pendulum)

How can I show that there is a minimum angular velocity $\omega_{min}$, different from zero, such that if we chose an $\omega$ smaller than $\omega_{min}$, then it is not possible to have a circular ...
0
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0answers
23 views

Overall Velocity of Body with Multiple Wheels

Let's say you have some object, a car or whatever, that has multiple wheels going in multiple directions, each of which can spin at different speeds. How would one go about getting the overall ...
0
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1answer
162 views

Falling dominoes

I have been attempting to determine the maximum velocity a line of dominoes can reach. I have found that there are two forces which act upon it: Initial impulse and gravitational force. As kinetic ...
0
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1answer
65 views

tangential acceleration and angular acceleration [closed]

$$r= 2 \text{ m}$$ $$a_{\text{tangential}}=\frac{\pi}{4} \text{ m/s}^2$$ for half a turn What is the angular velocity from rest of the circular path? $$a_{\text{angular}} = ...
0
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1answer
239 views

Calculating estimated HP from velocity, auto weight, and constant acceleration

I am working on a simulation program that runs theoretical performances of different cars and was wondering if there is a way to estimate the HP at any running RPM? the problem is (and this may be me ...
0
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2answers
356 views

Why is angular velocity of any point about any other point of a rigid body always the same?

I have the following question regarding an ideal rigid body. Firstly, is it always true without any exceptions that the angular velocity of any point about any other point on a rigid body is always ...
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0answers
211 views

Torque, angular velocity, keeping track of the rotation of a sphere

I'm trying to simulate a rotating sphere due to a torque on a specific point on the sphere. Say the sphere is connected to a string (so variable length) on the bottom, on $(r, \theta, ...
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1answer
229 views

A question about a body moving in horizontal circular motion

I have some related questions about a body moving in uniform horizontal circular motion: The body moves with a constant angular velocity on a rough horizontal surface. It is attached to a string that ...
6
votes
1answer
156 views

How much effort would be required to fix the Earth's rotation?

Given that the earth's rotation has been slowing down by very slight amounts over time, forcing us to introduce leap seconds and so forth into our clocks and calendars, I would like to ask if this ...
3
votes
1answer
300 views

Rolling a ball into a cone; what should the forces overall be?

This is my solution to finding angular displacement/velocity/acceleration on cone so far. Consider a cone, with an apex of half-angle $\psi$ pointing down, and a height of $h$. If I roll a ball into ...