The tag has no wiki summary.

learn more… | top users | synonyms

9
votes
4answers
993 views

Shape of rotating rope (lasso problem?)

Let's take a wire or a rope. I usually do this with a chain or my scarf. I fixate one end in my hand and apply rotation (by subtle movements of this endpoint like spinning a lasso). The rope gets ...
2
votes
3answers
2k views

Why did they add a Centripetal Force in the Free-Body Diagram?

problem ! solution ! Why do they have the centripetal force in there? I understand that the normal force is the centripetal force here, but why would they say "or $\frac{mv^2}{r}$"? I thought it ...
5
votes
1answer
228 views

Imaginary angle on simple centrifugal problem

Say somebody is spinning a mass on a string with a period $T$ around. If $T$ is very big, the mass will describe a small circle around the person's waist. If $T$ is very small, the plane of movement ...
1
vote
1answer
359 views

centrifugal force in static frame of reference

The other day we derived Kepler's third law. $$ \left( \frac{T_1}{T_2} \right)^2 = \left( \frac{r_1}{r_2} \right) ^3 $$ In order to derive this, you can look at a given planet that revolves around ...
0
votes
0answers
56 views

If Earth Were Filled with a Compressible Fluid and Spun Really Fast, What Hollow Would Form? [duplicate]

Possible Duplicate: What nonlinear deformations will a fast rotating planet exhibit? This is really a basic physics question that I wanted to check myself on because I'm not entirely sure ...
1
vote
1answer
149 views

Separation of solids from liquids using magnetic waves

Using magnetic forces, I want to separate solids from liquids in a solution as a centrifuge would do. Is there a way to hit a volume of liquid and get it to separate liquids and solids with heavy ...
3
votes
1answer
243 views

Equation of Motion in a Non-Inertial (Rotating) Frame

Let me preface my question by informing you this is for an assignment, so I would rather not have explicit answers but rather be given guidance in arriving at the correct solution. The question is ...
0
votes
1answer
290 views

calculating of g force in fun ride

we vistited yesterday a fun park and saw a ride which was a big centrifuge only in vertical. this one had a speed meter but it was broken and i also wanted to know how much g-force is on there... so ...
0
votes
1answer
146 views

calculating ballast needed to offset wobble of a 1g unbalanced centerfuge spinning at 20000G's

So this seemed pretty straight forward at first, but then I wasnt too sure about gravity forces... So. centerfuge 2 samples 1 sample is 1gram heavier than the other centerfuge at top speed is ...
0
votes
2answers
1k views

Negative g-force: difference between gravity and centrifugal force?

I was having a discussion with a friend about human tolerances of g-force. He believed that the maximum human tolerance of negative g-force is low, in the order of .5 g. I countered, saying that ...
3
votes
2answers
943 views

Could a human run horizontally inside a Wall of Death?

A popular circus stunt is for a motorcycle rider to ride inside a bowl shaped depression called a "Wall of Death." The rider goes higher and higher up the wall until they are actually horizontal. I ...
4
votes
3answers
439 views

Why don't astronauts in orbit get stuck to the “ceiling”?

When a shuttle is in orbit, it is essentially rotating around the "centre" of the Earth at a great speed. So why does there seem to be no centrifugal force sticking them to the 'ceiling' of the ...
30
votes
4answers
6k views

Why can't we feel the Earth turning?

The Earth turns with a very high velocity, around its own axis and around the Sun. So why can't we feel that it's turning, but we can still feel earthquake.
1
vote
1answer
297 views

Artificial Gravity - Spinning Station Questions II

In an answer to Artificial Gravity - Spinning Station Questions Vintage wrote: A theoretical space station of radius 900 meters, doing a complete rotation every 60 seconds (in order to generate ...
6
votes
2answers
548 views

Why don't we consider centrifugal force on a mass placed on earth?

Let us say a block of mass is placed on the surface of earth. Then while drawing the forces on that body, we say: Force $F = mg$ acting towards the center of Earth. Normal reaction $N$ offered by ...
3
votes
2answers
369 views

Mixing a cup of tea and break of centrifugal force [duplicate]

Possible Duplicate: Vortex in liquid collects particles in center Why when you mix a cup of tea with a teaspoon, tea-craps collect in the center of cup, instead of goes near the walls?
1
vote
0answers
871 views

What is the maximum non-fatal force withstandable by a human being for a short period?

Assuming any (optimal) body orientation/position relative to the direction of force and mechanism of death. I'd be interested in a rough estimate of threshold force and a suggested mechanism of ...
4
votes
4answers
9k views

How does centrifugal force work?

I know what centrifugal force is, but how does it work? Why are things forced to the outside?
2
votes
1answer
1k views

How many Gs would a driver of the Bugatti Veyron experience on the Ehra-Lessien track when cornering before record attempt?

Apologies if too specific. Watched a documentary National Geographic Megafactories Bugatti Veyron I told an colleague (engineer) about the need to warm the car up and then unleash it on the long ...
41
votes
7answers
4k views

Why is the Earth so fat?

I made a naive calculation of the height of Earth's equatorial bulge and found that it should be about 10km. The true height is about 20km. My question is: why is there this discrepancy? The ...
4
votes
2answers
2k views

“Artificial gravity” on a rotating space stations

There have been a lot of sci-fi shows recently using the "rotating space station" explanation for gravity on space stations. After watching these videos: ...
6
votes
3answers
693 views

Will a machine or a technique ever be possible that allows artificial gravity in interplanetary space?

Will a machine or a technique ever be possible that allows artificial gravity in interplanetary space? And I ask out of pure curiosity. I know there is the "Vomit Comet" that allows for a non-gravity ...
1
vote
2answers
456 views

Why is a suspended spinning body of liquid prolate?

Instead of a flat disc one would expect the centrifugal forces to push it in.. The body is not in a container but suspended in air spinning horizontally (i.e. left to right or vice-versa) - how to do ...
3
votes
1answer
391 views

Can we measure the “Tilt-A-Whirl” effect of the Earth+Sun orbiting the galactic hub?

You've probably ridden on the fairground ride called the "Tilt-A-Whirl", or--as Disneyland calls it--the "Spinning Teacups", as well as other fairground rides that employ epicycles. You can really ...
1
vote
2answers
6k views

Calculation of the G-force

I have a formula which is $\text{G-force} = \frac{v\omega}{9.8}$, where $v$ is speed and $\omega$ is the angular velocity. I've seen on the internet that G-force is actually $\text{acceleration}/9.8$. ...
31
votes
8answers
6k views

Why doesn't a bike/bicycle fall if going with a high speed?

Why does a bike/bicycle fall when its speed is very low or close to zero and is balanced when going with a high speed?
10
votes
1answer
7k views

Derivation of the centrifugal and coriolis force

I was wondering how easily these two pseudo-forces can be derived mathematically in order to exhibit a clear physical meaning. How would you proceed?