# rotating

1. ### Frame of Refrence on Rotating Earth

I have no idea where to start for looking for an answer to this question. At essence, I am confused how a photon knows it's frame of reference in laboratory experiments conducted on the earths surface. If a photon travels at the universal speed limit regardless of the velocity of the object...
2. ### Simple Mechanics problem - rotating the rod with a ball attached on a string

To the end [A] of the rod [AB] with a length of d = 1.35 m a thin string with a length of l = 1.16 m was attached, at the other end of which a ping-pong ball is attached. The bar began to rotate in a horizontal plane with a constant angular velocity ω = 2.08 / s around the end B. Find the radius...
3. ### induced emf in a solenoid due to a rotating magnet

Hey, I have come up with an idea for my EEI to measure the emf induced in a solenoid by a rotating magnet when the solenoid is not directly above the magnet (such that the magnetic field is not uniform). Previously I had to perform an experiment where the solenoid was on axis (see picture) and...
4. ### Rotating Cylinder

Any help to solve this problem? Thanks in advance
5. ### Normal Reaction in rotating frame.

Hi there, I'm new to this forum so forgive me if this is in the wrong section. The module I'm studying is a mechanics course as part of a mathematics degree (currently in year 3 of 4), however, I am not confident with physics at all. I have a problem with the following question . . ...
6. ### Friction of rotating disks

Two disks are laying on top of each other. The disks are rotating on the same axis, are made of different materials (different friction coeffs), and are rotating at different velocities. The aforementioned are all given in the problem. Is there an equation to calculate the energy lost due to...
7. ### Fizeau rotating cogwheel

The first measurement of c that didn't make use of the heavens was by Armand Fizeau in 1849. He used a beam of light reflected from a mirror 8 km away. The beam was aimed at the teeth of a rapidly spinning wheel. The speed of the wheel was increased until its motion was such that the light's...
8. ### Am I doomed to never understand the relativistic rotating disk?

Ok, I am really out of my depth here so I am wondering whether I can get any mileage with this with just flat minkowski space with uniformly rotating polar co-ordinates and some vector calculus and linear algebra? (I'm really not good with tensors). Is it worth me trying to understand some...
9. ### Cylinder rotating on a horizontal surface with friction

A hollow cylinder with mass m and radius R stands on a horizontal surface with its smooth flat end in contact the surface everywhere. A thread has been wound around it and its free end is pulled with velocity v in parallel to the thread. Find the speed of the cylinder. Consider two cases: (a)...
10. ### Man in a rotating spaceship

A spaceman, who weighs 75 kg on the Earth, is in a room of a spaceship that is rotating around the axis through the centre of the spaceship with angular speed \omega = 0,5 rad/s. The spaceman is on a weight scale and he sees that he weighs 70 kg. At what distance he is from the axe of rotation...
11. ### Lift a hemispherical dome on a level surface filled with water by rotating it

Hi, I have this problem where I am asked to find out which angular velocity I need to have to lift this 30 tons heavy dome with a hole on the top. I have attached a sketch and how I tried to solve it, but i get the wrong answer. Right answer is 1,95 rad/s. Thanks
12. ### Rotating and translation on a frictionless surface

A uniform spool of mass M and diameter d rests on end on a frictionless table. A massless string wrapped around the spool is attached to a weight m which hangs over the edge of the table. If the spool is released from rest when its center of mass is a distance l from the edge of the table, what...
13. ### Which is a simple yet accurate way to predict the type of flow in a rotating cylinder

Hi, I am trying to find an empirical formula/graph/simple calculation that I can use to predict the flow pattern inside a horizontal rotating hollow cylinder. I intend*to find a method by which I can understand the onset of different flow patters (i.e. annular, rimming, pool .etc) by varying...
14. ### Physical defect of Einstein transformation of coordinate system

(Shake)Physical defect of Einstein transformation of coordinate system
15. ### How to determine shear rate in rotating plate?

Hello, I was wondering how to determine shear rate in rotating plate as below. I believe the plate length (L) and height (H) should have influence on the magnitude of shear rate. What would be relationship between shear rate and plate length/height? Is there any publication about that...
16. ### How to determine shear rate in rotating plate?

Hello, I was wondering how to determine shear rate in rotating plate as below. I believe the plate length (L) and height (H) should have influence on the magnitude of shear rate. What would be relationship between shear rate and plate length/height? Is there any publication about that? Thank...
17. ### Rotating bar problem

H[ everyone, I have a problem which has me frankly stumped at the moment. I cannot see where I can go from here to progress toward the correct solution. The problem is as follows - A thin uniform 12.0 kg bar that is 2.0 m long rotates uniformly about a pivot at one end, making 5.00 complete...
18. ### Rotating Cone and Mass problem

Hi again .. I'm afraid I have another problem that's taxing my problem-solving abilities. I would appreciate a little help in how precisely to tackle this problem .. I'm stumped. Problem description - A small block with mass m is placed inside an inverted cone that is rotating about a...
19. ### Expected results from rotating Michelson–Morley like experiment?

I am wondering what results would a fast rotating version of Michelson–Morley experiment produce? I have been researching this topic for a long time now and I simply do not have any idea what the results might be. I would very much appreciate your opinion to two proposed thought "gedanken"...
20. ### Differing Units while Calculating Acceleration of Rotating Objects

Question on Acceleration of Rotating Objects: The Physics Textbook I have says that the Acceleration of a spinning object is the Pythagorean-theorum result of sides for Centripetal-Acceleration (toward the rotation center) and Tangential-Acceleration (perpendicular to Centripetal-Acceleration...