What is Centripetal force: Definition and 561 Discussions

A centripetal force (from Latin centrum, "center" and petere, "to seek") is a force that makes a body follow a curved path. Its direction is always orthogonal to the motion of the body and towards the fixed point of the instantaneous center of curvature of the path. Isaac Newton described it as "a force by which bodies are drawn or impelled, or in any way tend, towards a point as to a centre". In Newtonian mechanics, gravity provides the centripetal force causing astronomical orbits.
One common example involving centripetal force is the case in which a body moves with uniform speed along a circular path. The centripetal force is directed at right angles to the motion and also along the radius towards the centre of the circular path. The mathematical description was derived in 1659 by the Dutch physicist Christiaan Huygens.

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  1. I

    Investigation regarding the rotor ride

    So far some of the topics I can think of are Investigating how angular velocity affects the centripetal force experienced by riders on the rotor or the coefficient of friction required to pin the rider to the wall.
  2. SireJeff

    I Origin of Centripetal force when the net force toward the center is 0?

    to clarify , my purpose isn't to find a solution to my home work , I already did the home work and my thread is more a request of justification or at least a clarification of the forces at play. I need explanation on the general topic not the solution to my question, I am mentioning the question...
  3. Lotto

    What is density of dark matter as a function of distance from the galactic core?

    This problem builds on my previous post, where we calculated that core's mass is ##M_1=\frac{{v_0}^2r_1}{G}##. So if we consider mass of dark matter dependent on distance ##r## to be ##M_2(r)##, we can calculated it from ##G\frac{(M_2(r)+M_1)m}{r^2}=m\frac{{v_0}^2}{r}.## So...
  4. Lotto

    What is the mass of the Galaxy's core?

    It is clear that the speed is constant because dark matter hasa gravitational effect on stars, so when a star is further from the core, gravitational force of it is smaller, but the net gravitational force of dark matter is bigger. So the net force acting on each star has to be the same. So...
  5. S

    Washing machine - centripetal force

    During summer i wash light items - t-shirts, boxer shorts and low-cut socks, washing machine is just 1/4 full and it cant balance during spin properly. During winter with bigger items there is no such problem. So i was wondering, could a temporary solution be to just use some kind of basket...
  6. G

    B Why is speed constant when centripetal acceleration is constant?

    It's actually getting little boring and makes me angry why all the videos/articles show centripetal acceleration formula and presume that speed is constant. I want to prove backwards, i.e we know the constant perpendicular force acts on an object from the center and why object starts to move in...
  7. P

    I Where is the centripetal force acting on mass M?

    Look at the image below where I've drawn a rigid triangle, with thin lightweight rods and a fixed mass M attached as shown. There is a constant torque (2Fr) applied at a fixed pivot point P bisecting the top rod. Let's assume M is at rest and then a torque is added about pivot point P which will...
  8. C

    Loop the Loop Problem Solution | N > 0, Energy Conservation Method

    For this problem, The solution is, Does someone please know why ##N > 0##. I though at the min speed to still go around the loop, we could set ##N = 0## and ##mg## provides the centripetal force. Also, I am wondering how to do this problem with using energy conservation. My working is ## N +...
  9. Grizzly_1

    The advisory speed for a car on a sloped bend

    Hello all, I am sadly stuck on the last part of a circular motion question sheet I was given for homework. I have a mark-scheme with me, but it has actually given me more questions than answers. I have attached my working, and how I arrived at my answer, and the differences it has with the...
  10. Tanreom

    I How does a screw roll down an inclined plane?

    I was thinking about how various objects would slide down on an inclined plane, and I just couldn't figure this problem out. So let's say I have this screw or cone on its side, on an inclined plane. If friction exists, what would the motion of the screw be as it slides down the inclined plane...
  11. James Brown

    B How come friction can make a car turn?

    How is it possible that friction makes car turn? From what I know, frictional force is acting along to the direction of the wheel turns. When the car turns, the direction of the frictional force now act opposite to the direction of the wheel turns! I'm sure if you rotate the steering wheel to...
  12. J

    I Direction of friction of each wheel and total moment when a car turns

    Static friction is known to provide centripetal force when a car turns. Assuming uniform circular motion, my questions are 1. Is the static friction of each wheel points toward the center of turning circle or it's the combined forces of all four wheels that has to point toward the center of...
  13. A

    Roller coaster and centripetal acceleration

    See attached image. The solution to this problem calculates v2 at the top of the roller coaster ride. Why is that? Shouldn't you calculate v2 at the bottom of the roller coaster ride as you require the maximum velocity there to get around the loop?
  14. A

    I Confused about N*sin(theta) = (m*v^2)/r in banked curve

    If there is a car resting on a banked curve with angle theta, velocity v = 0, but N (normal)*sin(theta) > 0. So N*sin(theta) =/= (m*v^2)/r with v = 0. But my physics textbook just defined N*sin(theta) = (m*v^2)/r in banked curve. What is going on here?
  15. Send-Help

    Find tangential velocity given radius and the coefficient of friction

    I have attempted to solve for the velocity by setting the centripetal force (mv2)/r to the normal force pointed to the center of rotation (mg). This approach seems to give the incorrect solution and I am unsure of my misunderstandings.
  16. H

    Amusement Park Centripetal Force Question.

    Hi, I just had a question about this homework question. I am not given the mass at all in any portion of the question. Fs = Fc because the static friction is the thing that keeps the rider stuck to the wall My answer came out to about 3.4 m/s for the minimum speed that keeps the rider stuck to...
  17. crudux_cruo

    B Confusion while trying to build intuition of centripetal force

    As I understand it, when a body undergoes uniform circular motion its velocity does not change in magnitude but instead direction. This change in velocity, or acceleration, is directed inward towards the center of the circle. If a body was not experiencing a net centripetal acceleration, then...
  18. A

    I How is static friction the centripetal force during a car turning?

    Hello, as you can see i am trying to understand conceptually how the tires during turning create a centripetal force. It was explained to me that as we turn the car tires, the tires similar to a ski or a wedge, now want to push the ground to the side and forward. If the ground was loose, this...
  19. barryj

    Centripetal force on a person on the Earth

    I am confused. See my diagram below. With the Earth rotating, I think the scale would read the force of gravity or 448.4 N. If the Earth were not rotating, would the scale read less or more due to the effect of centripetal force? I tend to think more by an amount of 1.78 N. Is this correct? If...
  20. John_Dee

    Thought Experiment - Centripetal Force

    Ok, so we know that if one were inside a donut-shaped spaceship that is rotating around it's axis, that the passengers will experience centripetal force. It seems obvious to say that the ship is rotating relative to the nearby stars and planets. So far, so good. But... what if we removed all...
  21. J

    Displacement & Angle Theta: Figuring Out Centripetal Force

    For the displacement, how do I figure out the angle theta between the points? And how does the speed at which the string retracts affect the centripetal force?
  22. Caw

    Centripetal force problem involving a washing machine

    Summary:: Just want to know if I'm on the right track with this question. Hi, so this is what I have for my assignment: A washing machines drum is rotating rapidly about a vertical axis (a so-called toploader). A wet sock is stuck on the inside, halfway up the drum, and the drum begins to slow...
  23. T

    Help with centripetal force and friction question please

    Ff = Fc (mv^2)/r = kmg (v^2)/r = kg v^2 = kgr v^2 = 0.7*9.8*200 v = 37.04 m/s I chose option e, and its wrong. What am i doing wrong here?
  24. P

    Forces at the bottom of a rotating U-tube filled with water

    So when the rotation starts some water will move upwards and in the vertical part of tube. I know hat centripetal force will be given by F=mv²/r Now I though of taking r as centre of mass of the water system but I don't know what to take the value of m as? Should I only consider the water...
  25. Adesh

    How do we provide centripetal force in this situation?

    Situation: Let’s say we have a wire bent into a circular shape, there lies a bead through the wire and it can slide through it. The wire is kept in vertical plane and is swung along the axis AB. My question : How the centripetal force is provided to the bead? The bead will go into a...
  26. aspodkfpo

    Car turning and centripetal force

    1. When a car turns there is a centripetal force towards the centre. This centripetal force is labelled as a static frictional force. I don't understand where this static frictional force arises from. Friction is meant to oppose motion, but I don't see the motion that is parallel to the friction...
  27. brotherbobby

    Work done on a conical pendulum

    The diagram for the problem is shown alongside. In the vertical (##\hat z##) direction we have ##T \cos \theta = mg##. In the plane of the pendulum, if we take the pendulum bob at the left extreme end as shown in the diagram, we have ##T \sin \theta = \frac{mv^2}{r}## (the ##\hat x## axis of...
  28. caesium

    Centripetal force for off-centered cylinders rolling down a curve

    My initial attempt: Total Centripetal force on the cylinder would be given by $$\textbf{F}_{net} = mR\omega^2 \textbf{e}_1+mr_{cm}\omega^2 \textbf{e}_2$$ where the vectors e_1 and e_2 have magnitude 1 and point radially outwards (and continuously changing as the cylinder rolls down) as marked in...
  29. M

    Exploring Centripetal Force: Does Radius Influence It?

    Well i think centripetal force is inversely proportional to the radius, so I'm guessing it would decrease but not sure to be honest.
  30. ColoradoGrrrl

    Circular Motion: Write expression for the period in terms of r and g

    I'm not sure if I'm doing this right as far as coming up with the equation they are asking for. I feel the question is poorly worded and the formatting makes their equation notation difficult to understand. Any insight would be very helpful. This is my work so far:
  31. brotherbobby

    Tension in a rotating rod at various places

    (The answer given in the text says ##\boxed{T_1\; >\; T_2}## but, as I show below, I think it's just the opposite). I begin by putting an image relevant to the problem above. Taking a small particle each of the same mass ##m## at the two positions, the centripetal forces are ##T_1 =...
  32. M

    Centripetal Force: What Happens When Force Increases?

    Suppose, there is an object in a circular path that goes with a cirtain speed. What happens, if suddenly the centripetal force increases? a) The object remains in the path but its speed increases b) The object exits the circular path c) Any other situation Please, explain your answer, thanks
  33. M

    Centripetal force on a vehicle while cornering

    According to the Newton's third law "For every action, there is an equal and opposite reaction." When a car (or a bike) turns, How does the car (bike) exert force outward (in the opposite direction of centripetal friction force)?
  34. greenrichy

    Centripetal force while a car makes a turn

    Correct me if I'm wrong, but I think it is not possible to solve (1) with all the data that's given. As for (2), I have come up with the following solutions: (a) - The tension in the string acts as the centripetal force on the fuzzy dice (b) - The frictional force between the road and the car...
  35. N

    Help with a Centripetal Force Question

    I am not too sure as to how to approach part c. of this question. In the vertical plane, the centripetal force is provided by the normal force and the force of gravity. However, the solution to this problem includes a description of the forces at the top of the loop, where the normal force is...
  36. A

    Work Check - Centripetal force - Finding Tension in a Rope

    Homework Statement A man, with a mass of 85kg, swings from a vine with a length of 11m. If this speed at the bottom of the swing is 8m/s, what is the tension if g = 10m/s^2? Given: m (mass) = 85kg r (radius) = 11m V (speed) = 8m/s g = 10m/s^2 T = ? Homework Equations Fc (centripetal force) = T...
  37. N

    Centripetal Force Banked Curves

    Homework Statement This is a conceptual issue which I am trying to understand: When you are describing a vehicle traveling on a banked curve, force parallel (the force which is found to be parallel to the surface of the road pointing down the bank) is omitted from the FBD and the equations...
  38. Cc518

    A father spins his child on a cart

    Homework Statement The father stands at the summit of a conical hill as he spins his 20 kg child around on a 5.0 kg cart with a 2.0-m-long rope. The sides of the hill are inclined at 20 degrees. He keeps the rope parallel to the ground, and friction is negligible. What rope tension will allow...
  39. W

    Centripetal Lab- finding the mass from the slope

    Homework Statement The lab: Centripetal Force Lab a Rubber stopper is moving in a horizontal circle at a constant radius and it is attached to a string where at the bottom, there is a mass where the mass is 100g, 150g, 200g, 250, and 300g (can see image attached) from the lab, I collected...
  40. Beth N

    Centripetal Force: Find banking angle on a roadway

    Homework Statement Problem 6.7[/B] Radius of curve: 200m Speed: 90 km/h=90000m/h What should be the value of the banking angle if no dependence is to be placed on friction?Homework Equations ##F=ma## ##F_c=\frac {mv^2} {r}## ##w=mg## Trig functionsThe Attempt at a SolutionI got an...
  41. navneet9431

    Why does friction play the role of centripetal force?

    What makes frictional force the centripetal force of a car turning along a curve? As friction is the opposing force and acts anti-parallel so there is no component of frictional force towards the center,right? Then how can frictional force be centripetal force?
  42. J

    Exploring Centripetal Force and Energy Recovery in Space | Jerry Ray Walz Jr."

    This is supposed to be: Centripetal Force, not Centrifugal. This post is heavily edited. This post actually originated from me thinking about designing a space game, and the first thing that I think about when it comes to games and movies, is how unrealistic they are. So it may be quite...
  43. Tannerbobanner

    How does radius affect frequency in uniform circular motion?

    I am writing a lab report on the effect of the radius of a string on the frequency of rotation on an object in horizontal uniform circular motion. My hypothesis is: If the radius of the string from the origin of rotation increases, then the frequency will decrease because frequency has an...
  44. jybe

    Given speed/mass find R (centripetal)

    Homework Statement 1) A 50kg person drives a car at 8.3m/s over a hump in the road. At the top of the hump, the driver feels a force of 143 N from the seat. What is the radius of the hump? 2) At what speed will the car need to move over the hump for the person to feel weightless at the top...
  45. Jan Berkhout

    Having trouble working out centripetal force?

    Homework Statement The Russian Mir space station had a mass of 130 tonnes and orbited Earth at an altitude of 480km with an orbital speed of 7621.4m/s. The diameter of Earth is 12 760 km. a) What centripetal force was acting on it? b) Find the value of the acceleration due to...
  46. P

    Why is the force of the spring equal to the centripetal force?

    Homework Statement A string is rotated around a point with a radius of 4 meters. Calculate the potential energy stored in the spring Homework Equations F = KX The Attempt at a Solution The solution to the problem involves making the force of a spring equal to the centripetal force. I don't...
  47. isukatphysics69

    Find acceleration and centripetal force

    Homework Statement Rank the rate at which the direction of each object's velocity is changing, greatest first. Homework Equations n/a The Attempt at a Solution I know a centripetal = v^2/r, but i don't have r so i am not sure if i am supposed to just eyeball it and draw a reference circle or...
  48. E

    Can gasses be contained with centripetal force?

    Not sure if this is the right place to post or even a stupid question but anyway. If you had a chamber of gas and released it out of a barrel with force it would disapate into the air right? My question is, if you were to do this but somehow spin the gas particles so that they held themselves...