any force responsible for maintaining an object on a curved path around a fixed center. In introductory coursework this is usually "uniform circular motion" and yields several simple and useful relations. Not to be confused with the centrifugal pseudo-force experienced in a accelerated referenced ...

learn more… | top users | synonyms

44
votes
8answers
5k views

Does centrifugal force exist?

Currently in my last year of high school, and I have always been told that centrifugal force does not exist by my physics teachers. Today my girlfriend in the year below asked me what centrifugal ...
38
votes
6answers
5k views

Pouring water in an aircraft while upside down?

What is the physics behind the following photo? Someone had told me that this is because the aircraft might be moving towards a lower altitude, but I am still not sure.
10
votes
3answers
777 views

Centrifugal force?

Everyone calls it a pseudo force and that it is not really present, even there are so many machines listed to advantage of centrifugal force ( centrifuge, washing washing drier),and also it has the ...
9
votes
4answers
2k views

What is the cause of centripetal/centrifugal force?

What is the cause of centripetal/centrifugal force? When an object of mass $m$ is moved in a circular orbit, it experiences a centrifugal force radially away from the center. What is the cause of this ...
9
votes
3answers
273 views

Can an orbit be calculated using two points and transit time?

Working in only two dimensions and assuming that the central body is at the origin of the coordinate system, given two points in space and knowing the transit time between those points, as well as the ...
9
votes
4answers
874 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 ...
8
votes
2answers
2k views

Relativistic centripetal force

The thought randomly occurred to me that a circular particle accelerator would have to exert a lot of force in order to maintain the curvature of the trajectory. Many accelerators move particles at ...
6
votes
10answers
365 views

Why is centrifugal 'force' perpendicular to line of inertia

I know that centrifugal is labeled a fictitious force only arising in a rotating reference frame, but I still struggle to understand the forces at play intuitively in tethered rotating bodies. I've ...
6
votes
2answers
237 views

Effect of water on wobble of rotating structure

If we have a structure that rotates to create artificial gravity, then if the mass isn't perfectly distributed along the circumference the CM will be offset from the geometric center so there will be ...
5
votes
5answers
2k views

Turning an Airplane. What actually causes the circular motion in a banked (roll) turn?

Basically I'm wondering if this is correct. Which essentially says that you need a torque to get the nose of the craft to turn and that this is provided by the rear tail surfaces. After trying to ...
4
votes
4answers
1k views

Increasing mass' effect on the balance between centripetal force and centrifugal force

Okay, this is nothing more than a thought experiment which popped into my head while driving home from work today. Take the case of a single body orbiting another, larger body, as in a planet and a ...
4
votes
0answers
566 views

Friction in circular motion [closed]

A circular horizontal table spins around its axis of rotation with a constant angular speed. It completes one revolution in 2 seconds. An object whose mass is $M = 0.8 \ \text{kg}$ is placed on the ...
3
votes
3answers
627 views

Centrifugal Force

When a body is in circular motion, realistically, it experiences only the centripetal force, created by gravitational pull, tension etc. , which gives it acceleration towards the centre. Now, assuming ...
3
votes
3answers
2k views

What provides the centrifugal force for planets orbiting a star?

this is a question I had when I was a kid. I'm a bit ashamed because I think I am missing out on something very obvious since I have the same question despite almost being an engineer now! From ...
3
votes
3answers
482 views

Physical Variables of Circular Motion

To me, the definitions of variables involved in circular motion are rather confusing (perhaps due to the lack of understanding on my part), hence the question. As I understand it, there are two ...
3
votes
3answers
325 views

Conical vs Simple Pendulum

I don't understand why the Tension $T$ on a conical pendulum and a simple pendulum are different. In a simple pendulum, one would say that the tension of the rope is $T=mg \cos(\theta)$. However, ...
3
votes
3answers
1k views

The force arrow for centripetal force points in the opposite direction of my calculation?

I need someone to clarify a conceptual problem I can't seem to surpass. Image there is a rollercoaster loop and a rollerbcoaster car enters the loop at high speed. Once the car completes the full ...
3
votes
2answers
265 views

Car on a frictionless banked curve

A car is on a banked curve, following a path which is part of a circle with radius $R$. The curve is banked at angle $\theta$ with the horizontal, and is a frictionless surface. What is the speed ...
3
votes
1answer
84 views

Pendulum in a Turning Airplane

My friend and I are having an argument over what happens with a pendulum hanging inside an airplane during a turn. Assuming that the airplane is making a standard 1 G coordinated turn, how does the ...
2
votes
6answers
567 views

Centripetal Force Acceleration

In uniform circular motion, acceleration is $\frac{v^2}{r}$ and time which it acts $\rightarrow 0$. So $\Delta v = 0$, but then why/how does direction change, when the acceleration should be ...
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 ...
2
votes
1answer
128 views

What provides the centripetal force for a glider?

Whenever any object follows a circular path, there is always a centripetal force which is provided by something. However, in the case of a glider making a loop in air, what provides the centripetal ...
2
votes
3answers
435 views

How you feel in outer space vs. orbit?

I understand that when someone is in low earth orbit, the "pull" of their inertia is equal to the pull of gravity. However, the force of gravity is still acting on them. However, if they are in outer ...
2
votes
2answers
62 views

Could two identical stars revolve around each other in a common orbit if we only account for Newtonian physics?

Both a parent star and its planet revolve around the center of mass of the system, the reason we see stellar wobble. But if we take this to be true, which it is, there can be a configuration in which ...
2
votes
1answer
539 views

When does centripetal force cause constant circular motion?

As far as I know, if an object has a speed $s$ and a force is applied to it which generates an acceleration of $s^2/r$, then the object will start moving in a circle of radius $r$. Also, as far as I ...
2
votes
1answer
109 views

Vortex Air Intake

Why is a vortex air intake in an engine cause the fuel to burn more efficiently within a vehicle. Why is this more efficient.
2
votes
4answers
647 views

why does what get pushed away when centripetal acceleration is towards the center

If centripetal acceleration is towards the center, then why - when you spin a bucket of water (a classic demonstration) - does the water not get pushed out but rather stays in the bucket without ...
2
votes
1answer
40 views

Gas pressure and centrifugal force

I think about a rotating torus (simplified tire) filled with ideal gas. Mass of gas is $m$ and molar mass is $M$. Pressure in non rotating torus is $p_0$. Temperature is constant $T$. Inner radius of ...
2
votes
1answer
148 views

How is circular motion possible on a banked road when there is no Friction?

It is given here that the maximum safe speed of a vehicle on a banked road having coefficient of friction $0$, is $V =\sqrt{R g \tan \theta}$, where $\theta$ is the angle of banking. I can't ...
2
votes
2answers
189 views

Centripetal force in frame of reference of body moving In a circle

Suppose a body is moving in a circle about a fixed point. In the frame of reference of the body, is the centripetal force felt or is only the centrifugal force felt? More generally, does a body only ...
2
votes
5answers
430 views

Find drag force on link of rotating chain

Given a closed chain with a total length of 1.2m rotating at 1'800 rpm and a total mass of 0.4kg, what is the drag force pulling on one chain link? I originally thought that since no link size was ...
2
votes
3answers
45 views

Turning on a straight, unbanked, frictionless road

I was learning about circular motion when this question struck me: In real life situations we are able to take a turn along a circular arc with our bike because friction provides us the necessary ...
2
votes
1answer
90 views

A bomb can be made to explode or implode? [closed]

A bomb can be made to implode or explode. Can one be made to explode while creating a vortex at the same time?
2
votes
1answer
515 views

Circular Motion Equation Derivation

I am given a series of three equations, which someone has used to determine the Tension force in a rope swing: $$mgh=1/2mv^2$$ $$T-mg=\frac{mv^2}{r}$$ $$T=3mg=1764N$$ I am asked to exaplain the steps ...
2
votes
0answers
220 views

Loop-the-Loop with Friction [closed]

Let's consider a track that begins vertically becomes a 450 degree loop, and level off. (See diagram) We drop a block from height $H$ that falls and goes around the loop. Ignoring air resistance, ...
1
vote
2answers
468 views

Do centripetal and reactive centrifugal forces cancel each other out?

In order for a body to move with uniform velocity in a circular path, there must exist some force towards the centre of curvature of the circular path. This is centripetal force. By Newton's Third ...
1
vote
2answers
141 views

Proof of centripetal acceleration formula ($a_c = \frac{v^2}{r}$) for non-uniform circular motion

The formula for centripetal (radial) acceleration is well known, and there exist many proofs for it: $$||a_c|| = \frac{||v||^2}{r}$$ However, all the proofs I've seen rely on the fact that it is ...
1
vote
2answers
310 views

Friction as a Centripetal Force

When an object is moving in a circle, won't the frictional force oppose it's motion? And if the velocity is always tangential to the path, there is no component of it towards the center, so there is ...
1
vote
2answers
320 views

Intuitive understanding of centripetal vs. centrifugal force

I am having trouble understanding how centripetal force works intuitively. This is my claim. When I have a mass strapped on a string and spin it around, I feel the mass pulling my hand. So, I want ...
1
vote
3answers
2k views

Centripetal force of a rotating rigid body?

Consider someone pushing a roundabout in a playground. Initially the roundabout is stationary, but when it is pushed, it rotates with increasing rotational speed. The force of the push is ...
1
vote
2answers
65 views

Effect of spin on gravitational field?

If a large sphere of uniform density is spinning around one axis, is its gravitational field uniform? If yes, then what if it's not a sphere or not uniform? For example if we remove a chunk of the ...
1
vote
2answers
194 views

Vertical uniform circular motion.. can it really be uniform? [closed]

This is the picture in my mind: For centripetal force, I learned that: $T-mg\cos\theta= \frac{mv^2}{r}$ In vertical circular motion, the velocity is naturally going to decrease as kinetic energy ...
1
vote
3answers
413 views

Is it possible to whirl a point mass (attacted to a string) around in a horizontal circular motion *above* my hand?

I'm studying circular motion and centripetal force in college currently and there is a very simple question but confuses me (our teacher doesn't know how to explain either :/), so I hope we can sort ...
1
vote
2answers
146 views

Please explain this circular movement problem [closed]

I was working over some problems from my physics textbook, and I came across this one, it involves circular movement: A car with the mass of 1t is moving over a hill with the velocity of 20 m/s. The ...
1
vote
3answers
41 views

Uniform Circular Motion and Centripetal Acceleration

In introductory physics books (or at least mine) it limits the equation $a_c=v^2/r$ to the situation where the speed around the circular path is constant. It enforces the idea that the speed is ...
1
vote
2answers
193 views
1
vote
2answers
35 views

Why does a string remain taut in circular motion

Lets say an object is tied to a string and it is being swung in a circle: In this case, the tension of the string acts as a centrifugal force that keeps the object moving in a circle. However, if ...
1
vote
1answer
29 views

UCM unidentified force

A train rounds a curve of radius 235 m (turning right). The train track is flat, and the train is traveling at a constant speed. A lamp in the train makes an angle to the vertical of 17.5 degrees. ...
1
vote
1answer
53 views

Motion of a car rounding a bank

When a car is traveling round a banked track as fast as possible, it has a tendency to slip up the slope. Opposite in the case when the car travels slowly and has a tendency to slip down. Can ...
1
vote
1answer
61 views

Reference frame and centrifugal force

Imagine you are on a theme park ride in which you sit in a car and are spun around in a circle, basically like a giant centrifuge. An observer from the outside would say that there is no centrifugal ...