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.

View More On Wikipedia.org
Recent contents Top users
  1. jaumzaum

    Understanding Centripetal Force: The Confusion Behind Car Skidding Explained

    Hi everyone, Maybe it could be an idiot question but I've never know why. If centripetal force points to the center, Why a car making a turn tend to skid to away of the road? I mean, there would have to be a force opposite to centripetal, that is in fact, greater than it, for the...
  2. S

    Warm air rising vs centripetal force

    I assume this is the correct forum for this question... :P This is the idea: we have a hollow object (probably a sphere or cylinder), attached to a tether, rotating around a central body. The dimensions and speed I don't have specifics for and shouldn't matter: the point is, centripetal force...
  3. N

    Exploring Centripetal Force: Understanding the Physics Behind Circular Motion

    Hi, I got 2 questions concerning Centripetal force. I am thankful for every answer I get ! 1) Let's say a car is driving very fast in a loop with radius r on Earth where air resistance and friction doesn't exist. Let's say the car's engine stops and when the car gets to the top of the loop...
  4. 5

    Centripetal force lab: meaning of slope of radius vs Fc graph

    Homework Statement I have a graph with the radius on the x-axis and Fc on the y axis. I had to then calculate the slope of this linear relationship. I did that, and I got 0.17. The problem is that I don't know what this represents. mass? acceleration?? Homework Equations Fc = m4π^2rf^2...
  5. R

    Question about Centripetal Force

    Hi For a car making a turn, the friction between the tires causes the centripetal force, but how come in FBD I always see the centripetal force being drawn acting on the center of mass and not the point of contact between the wheels and the ground? Similarly, if I was dragging a pick of...
  6. S

    Centripetal force and tension in a string

    Hi everyone. I've seen this question posted before so I apologize, but I have a hard time understanding the responses and some posts in different threads seem to go different directions (I don't know what to follow!). I've given the problem a try and would greatly appreciate knowing if I'm on...
  7. J

    Calculating the Centripetal force of a trebuchet

    I need help with calculating the centripetal force of a trebuchet. I have tried to derive an equation from a free body diagram, but I am sure that I'm doing something wrong. Does anyone know how to calculate the centripetal force?
  8. R

    Does radial velocity affect centripetal force

    If for example someone is walking along a radial line of a spinning disc at constant velocity would they experience a different centripetal force than if they were standing still at that particular location (I know the person would experience jerk while moving along, but would they experience a...
  9. R

    How Does Centripetal Force Affect the Tension in a Whirling Rock on a String?

    The situation is like this, You're holding a string with a rock at the end of it. You hold the string above your head and whirl the string. It's going to make an angle with the vertical, so its not 90 degrees. So if I break it into components, Ft (tension) * cosX will be the vertical...
  10. M

    Centripetal force and satellite

    Homework Statement If a satellite drops to a lower orbit, how does this affect its centripetal force, period, tangential speed, and angular velocity? Homework Equations Fc=m(v2/r) The Attempt at a Solution Because of the formula above, the satellite experiences an increase in Fc...
  11. O

    Determining a centripetal force proportionality equation

    Homework Statement In a lab, we essentially used an apparatus similar to this: In three experiments with several trials, we varied three things: centripetal force (the mass of the bottom), radius (of the circle by adjusting the alligator clip), and mass (rubber stopper). The trials were...
  12. M

    Centripetal Force; calculating speed

    Homework Statement A wet towel, of mass 0.65 kg, travels in a horizontal circle of radius 26cm in the spin cycle of a washing machine. The frequency of rotation is 4.6Hz. a)Name the force causing the centripetal acceleration. What object exerts that force? b) What is the speed of the...
  13. ThomasMagnus

    Circular Motion: Exploring Centripetal Force

    Hello, I am currently studying circular motion, and I would like to know if the statements I have made below are correct. -------------------------------------------------------------------------------------------------------------------------- The centripetal force is the sum of all...
  14. J

    Centripetal Force Homework: Solving for F with F = ma

    Homework Statement I did an expirement in my physics lab on centripetal force. I'm doing the calculations and right now I am calculating the centripetal force using equation: F= (mass)(angular speed squared)(average radius). My answers are coming out to be huge numbers. ex: (148.8g)(52.70...
  15. M

    Centripetal Force: What Causes It?

    Hello everyone I know my question might be strange and stupid but I have to ask it! When an object attached to a string and moved in a horizontal uniform circular motion, the tension of the string will point to the center of the circular motion, right? Well, I can't see why! I know that the...
  16. T

    Relativistic centripetal force question

    The last post in the thread https://www.physicsforums.com/showthread.php?t=466305 seems to say that the relativistic force on a mass moving on a circular path is the centripetal acceleration, v*v/r, times rest mass times gamma squared. But the articles...
  17. A

    Why does gravity dictate min.velocity for centripetal force?

    Homework Statement You are playing with a yo-yo with a mass of 225 g. The full length of the string is 1.2 m. You decide to see how slowly you can swing it in a vertical circle while keeping the string fully extended, even when the yo-yo is at the top of its swing. (a) Calculate the minimum...
  18. A

    Carnival ride Centripetal force question

    First, please forgive my ignorance, as I do not really know enough to ask this question properly. In the carnival ride, Barrel of Fun, the centripetal force holds you against the wall of the barrel while it spins. As anyone who has ridden this ride knows, you can feel the force holding you...
  19. P

    Centripetal force satellite orbiting problem

    Homework Statement Question 1: What speed must a satellite have to orbit the Earth at a distance 7.8 x 10^7 m/s from the Earth's centre, where the acceleration due to gravity is 0.065 m/s^2? Question 2: An object orbits the Earth at a constant speed in a circle of radius 6.38 x 10^6 m...
  20. P

    Problem involving centripetal force of a circle

    Homework Statement Here is a diagram: http://i55.tinypic.com/k18g14.jpg A ball of mass 0.75 kg on the end of a cord is swung in a circle of radius 1.5 m with a period of 1.5 s as shown in the diagram. a.) What is the speed of the ball? b.) What is the acceleration of the ball? c.) What...
  21. T

    Centripetal Force + Frictional Force + Braking

    Homework Statement Assume that the driver of a car begins to brake his car when the distance from his car to a wall is 107 m. The mass of his car is 1400 kg, and its initial speed prior to braking is 35 m/s. The coefficient of static friction is 0.50, and assume that the car's weight is...
  22. T

    Roller Coaster Car Normal Force: 3693 N and -1307 N at Various Velocities

    Homework Statement A roller coaster car has a mass of 1200 kg when loaded with passengers. As the car passes over the top of the circular hill of radius 18 m, its speed is not changing. What are the magnitude of the normal force and the direction of that normal force with the below conditions...
  23. A

    Solve Centripetal Force Equation for Pivot Point

    as you all know the equation for centripetal force is (m((2 pie r)/t)^2)/r). ok so imagine this. a weight attached to a string attached to a pivot point. the weight is rotating around the pivot point. the pivot point can move back and forth along the x axis. if looking at a x, y graph. the pivot...
  24. R

    Hard Physics Problem - Centripetal Force

    Homework Statement A popular amusement ride operates as follows: Riders enter the cylindrical structure when its stationary with the floor. They then stand against the wall as the cylinder then begins to rotate. When it is up to speed, the floor is lowered, leaving the riders suspended against...
  25. E

    Roller Coaster + Centripetal Force

    A roller coaster car is on a track that forms a circular loop in the vertical plane. If the car is to just maintain contact with the track at the top of the loop, what is the minimum value for its centripetal acceleration at this point? g downward g upward 0.5 g downward 2 g upward...
  26. B

    How Do You Calculate an Astronaut's Orbit Around the Moon?

    Homework Statement While 2 astronauts were on the surface of the moon, a third astronaut orbited the moon. Assume the orbit to be circular and 100km above the surface of the moon. If the mass and radius of the moon at 7.40x10^22kg and 1.70x10^6m respectively, determine (a) the orbiting...
  27. B

    Centripetal force in a semicircle

    is there centripetal force in a semicircle?
  28. 8

    Problem with relationship of mass and radius with time in centripetal force

    We did a experiment, and the aim was to find out that relationship between mass and radius with period of time in the circular motion..Although I know the formula for centripetal force, but I am not sure about what the expression should be The lab data : Table 1: 1st experiment ...
  29. ShayanJ

    Centripetal force in a curved road

    I read in the jearl walker's fundamentals of physics,that the centripetal force for a car moving in a curved road,is static friction.But as we now static friction is the result of another force and can't be existed alone.what is the force causing this friction? thanks
  30. P

    Understanding Centripetal Force in a Rubber Ball and String Lab

    Homework Statement I did a lab where there was a glass tube with a rubber ball attached and a string hanging from the glass tube with metal washers attached at the bottom. My question is if the ball were to hang too low why would the centripetal force be less accurate is it because there...
  31. R

    Loop the loop problem with centripetal force

    Homework Statement A small block of mass m = 5kg slides along the frictionless loop-the-loop track shown in the figure. R = 2m a) If it starts from rest at P, what is the resultant centripetal force acting on it at Q? b) At what height from the bottom of the loop should the block be...
  32. P

    Centripetal Force Problems: Banked Road Formula & Frictional Force Calculation

    Homework Statement prob1) For a car traveling with a speed v around a curve of radius r, determine a formula for the angle at which a road should be banked so that no friction is required. prob2)Calculate the frictional force needed for a 900kg car traveling around a 500m radius curve at...
  33. W

    Centripetal Force and Force due to gravity?

    Homework Statement So I'm doing a lab of examining circular motion and centripetal force. My results came out to be that as Fg increases, Fc decreases. My question is if this relationship between Fg and Fc is logical and why? The experiment was conducted in a way that a ball was attached to a...
  34. B

    Binary-star system, gravity + centripetal force question?

    1. In a certain binary-star system, each star has the a mass of 1.36e30 kg, and they revolve about their center of mass. The distance between them is 1.1e8 km. What is their period of revolution in Earth years? 2. gravity = centripetal force (g*m*m)/d^2 = (mv^2)/r 3. I've tried plugging in...
  35. C

    Calculating Earth's Centripetal Force: Impact on Weight and Direction at 700mph

    Considering Earth spins there is a centripetal force acting on us. How much force is acting on us? Say a 1Kg weight? Can someone give me an equation? Is it significant? I was wondering if land racer would be noticeably lighter or heavier if traveling in one direction or another at 700mph due to...
  36. D

    Symbolic Centripetal Force Problem on WebAssign

    Homework Statement A car traveling on a flat (unbanked), circular track accelerates uniformly from rest with a tangential acceleration of a. The car makes it one quarter of the way around the circle before it skids off the track. From these data, determine the coefficient of static friction...
  37. C

    Centripetal force in vertical circles

    Homework Statement You have been asked to design a roller coaster track with a circular vertical loop in it. The loop is to have a radius of 10.0 m. How fast would the roller coaster have to be traveling so that at the bottom of the loop, the passengers will feel as if the seats are pressing...
  38. V

    Centripetal force ( Swinging a bucket in a vertical motion )

    First of all, the situation is as follows : A girl is swinging a bucket filled with water, and she is whirling it around in a vertical motion. When the bucket is at any other position on the circumference of the circle, everything seems fine and intuitive. But an interesting thing...
  39. X

    Magnitude of centripetal force acting on a roller coaster at the top of a loop

    Homework Statement A roller coaster goes through an inside vertical loop at the minimum speed required to just barely make it through the top of the vertical track. At the very top of the track, the magnitude of the centripetal force acting on the 'coaster is a. mg. b. 2 mg. c. 6 mg. d...
  40. J

    Solving a Centripetal Force Problem with Tension and Velocity | Homework Help

    Homework Statement I'm having a hard problem conceptualizing this. It states that an object with a certain Mass M is being spun in a vertical circle. The object attached to a rope, and the object moving in circular path with constant radius. It also give you the velocity of the object. It asks...
  41. S

    Centripetal force and acceleration problem

    Homework Statement A 2500 kg car starts from rest and travels along a circular track with a radius of 55.0 meters. The car starts out at a position due East of the center of the track, heading due North initially around the track, which is counterclockwise. The car increases its speed by 105...
  42. J

    Centripetal Force Loop-the-loop

    Homework Statement There is a loop-the-loop, thing, and a dude on a bicycle is going to ride around the loop. Total mass is 1 kg (I'm aware that isn't realistic at all...) and radius is 10 meters. a) what is the minimum speed that the cyclist must have to make it over the top of the loop...
  43. Telemachus

    Normal force as centripetal force

    Homework Statement Hi. I have this problem: A particle of mass m, rests on top of a frictionless sphere of radius R. Admitting that part from the rest for the position indicated in the figure along a path contained in a vertical plane. Get the value of the angular coordinate at the instant...
  44. L

    Spring Force as Centripetal Force?

    Homework Statement A 2.1 kg mass is connected to a spring with spring constant k=150 N/m and unstretched length 0.18 m. The pair are mounted on a frictionless air table, with the free end of the spring attached to a frictionless pivot. The mass is set into circular motion at 1.4 m/s. Find...
  45. A

    Centripetal force on a curved bridge

    Homework Statement When a car is speeding over a curved surface e.g a bridge, it sometimes loses contact with the ground. We have seen this many times in high speed chases and rally driving. In this scenario, the textbook wrote this equation: S-mg =Mv^2/r The RHS side is obviously the...
  46. K

    Calculating Centripetal Force on Moon & Earth: Mass, Distance, and Acceleration

    Homework Statement I)The mass of the moon is 7.35*10^22 kg. In inertial coordinates, the moon orbits the Earth in 27.3 days at an average distance of 3.84*10^5 kg. Calculate the centripetal force on the moon. II)The mass of the moon is .0123 times that of earth. Since the Earth is...
  47. P

    Centripetal force and total force?

    Homework Statement A 25 kg child is on a swing, which has a radius of 2.00 m. If the child is moving 4.0 m/s at the bottom of one swing, what is the centripetal force exerted by the ropes of the swing on the child? What is the total force exerted by the ropes when the swing is at its lowest...
  48. M

    Centripetal force of an ice skater

    Homework Statement A 55.5 kg ice skater is moving at 4.02 m/s when she grabs the loose end of a rope, the opposite end of which is tied to a pole. She then moves in a circle of radius 0.807 m around the pole. (a) Determine the force exerted by the horizontal rope on her arms. (b) Compare this...
  49. S

    Calculating Maximum Speed on Banked Curve: Centripetal Force

    A highway curves to the left with radius of curvature R = 46 m. The highway’s surface is banked at θ = 26 so that the cars can take this curve at higher speeds. Consider a car of mass 1018 kg whose tires have static friction coefficient µ = 0.57 against the pavement. The acceleration...
  50. S

    Centripetal force- Car making a turn

    Hello everyone, I have got confused with this. Normal the friction force acts to cancel the force. If I travel with 10 N force and friction is 5N, I travel at 5N. Why is that when you make a turn they don't create a net force, but act as separate forces?
Back
Top