# Tagged Questions

Circular motion about a central point or axis

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### Does adding mass to the fan blades affect its max velocity?

If I replaced fan blades with congruent blades, the only difference being the second set has a higher density, would that affect the speed cap on the spin? I know it would affect acceleration, but I ...
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### Rotation of a vector

Is a vector necessarily changed when it is rotated through an angle? I think a vector always gets changed because its projection will change, and also its inclination with axes will always change. ...
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### What is the difference between translation and rotation?

What is the difference between translation and rotation ? If this were a mathematics site, the question would be at best naive. But this is physics site, and the question must be interpreted as a ...
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### Derivation of Specific Rotation formula?

This is sort of a weird question, so bear with me: I was reading about how chiral molecules rotate plane polarized light and decided to think of a "logical" formula for expressing the amount that ...
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### Why anticlockwise movement is present in the whole universe [closed]

Why electronic movement in its orbit and planet orbital movement along with milky ways have anticlockwise movement. is there any specific reason. The Sun is rotating anticlockwise from its axis as ...
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### Dampening a swinging mass

Suppose a bar (black) sitting on a suspended ball (blue) has two rigid loads attached to it (red, green): Because the bar sits on a ball, the bar can swing clockwise or anti-clockwise. Suppose the ...
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### Force at axis of spinning wheel

This is a newbie question, but I don't quite understand the forces at work when an object is rotating. So I've read that i can use my right hand to determine the direction of the force at the axis ...
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### Vertical circular motion(with gravity)

Let's say I have a stone tied to a string and swing it vertically upwards. Now, if I provide an initial velocity such that the velocity of the stone = 0 at an angle greater than 0 from the horizontal(...
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### A point on a disc travelling at the speed of light [duplicate]

This might be a duplicate of this. I had an interesting thought experiment: suppose that you have a disc of a 1 m radius, where a point P2 inside the disc travels at the speed of light. You have a ...
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### Pointer to reference for rotational dynamics for large torques?

It's my understanding that when dealing with rotational dynamics (e.g., a gyroscope like at time=2155 seconds of https://youtu.be/N92FYHHT1qM?t=2155) that the equation for relating the speed of ...
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### Why does a fan blade appear to spin backwards when spun really fast?

This a phenomenon which I notice everyday but never really took an interest in. Why does a fan (or any other rotary object), when spinning really fast, 'appear' to slow down, upto a certain rpm, then ...
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### What are phase conventions in angular momentum and rotation calculations?

I work with complicated angular momentum calculations related to atomic physics; nevertheless, I never need to use anything related to a phase convention (apparently because it's taken care of in a ...
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### Direction of deflection of Coriolis force on Earth

I'm a bit confused about Coriolis force direction on Earth. The observed deflection is to the right in the northern emisphere and to the left in the southern one. But what about an observer in the ...
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### How to calculate the acceleration, if the mass-center is not on the force-vector's line (2D)

In a 2D plane there is an object, whose center of mass is at the $P$ point. The mass of the object is $m$. We apply a force $\vec F$ at the point $A$. If the center of mass is on the line, defined ...
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### Why rotating reference frames are not inertial? [duplicate]

Let's say I'm standing on the equator, and that there is no other reference point in the sky. If the planet is rotating, then I measure my weight to be lower than if it is not. But given that I have ...
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### Rolling without slipping taking the contact point as pivot

I'm confused about this "rolling without slipping" kind of situation. Or better in this case the object is rolling and slipping, just use the label "rolling without slipping" to identify the kind of ...
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### Moment of Inertia for objects moving in a circle?

I have been treating objects moving in a circle as a hoop, where $I=MR^2$ and it's been working but I feel like it works for a different reason from what I'm thinking. How do you actually find the ...
For example, a solid disk rolling down a hill would include both rotational and linear kinetic energy. For the rotational kinetic energy ($\frac{1}{2}I\omega^2$) the angular velocity becomes $v/r$ but ...
So, in my homework I am given the radius and also the tangential speed $v$, the measurement for radius is meters; the measurement for $v$ is $m/s$. I don't understand how by after calculating the RPM ...