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. M

    Centripetal Force Lab Questions?

    So we did a lab in physics today and it was a contraption where we had a stopper on one get of the string, and weights on the other, and we spun the stopper around, and there's 4 questions that i don't under stand, so if you could help me with this, and please explain as i want to know how to do...
  2. P

    Serious problem with centripetal force

    Homework Statement The soluble problem We have a disc, horisontal, which is rotating 0.5 revolutions per second. A block is placed on this disc with the mass 0.6 kg and 0.2 meters from the shaft. First, I convert 0.5 rates per second to T = 2 seconds. w = 2∏/2 --> w = ∏ --> m = 0.6 kg -->...
  3. P

    Centripetal Force - My conclusions are correct?

    Homework Statement I'm supposed to give the three forces acting on the basket on a carousel. Homework Equations Principly not for this task. The Attempt at a Solution When I look at the forces on the baskets on the carousel in constant rotation, I can point out the three...
  4. M

    Centripetal Force and ball of string

    Hello, could someone look over my answer? I am not very confident I did the problem correctly. Homework Statement A 76-kg ball is tied to one end of a massless string of length The other end of the string is tied to a nail in the center of a table. The ball is set into uniform circular...
  5. E

    Centrifugal Force, Centripetal Force, and Space

    I've got a weekly physics assignment, and I've been racking my brain on it. Any input on the accuracy of my response, what I could do to improve it, and where I may have gone wrong? Homework Statement Some years ago, a newspaper story contained the following statement" "The space shuttle...
  6. M

    Rotating Spacecraft Causing 'Artificial Gravity' via Centripetal Force

    How is this possible? The reason spinning a bucket of water upside down keeps the water inside the bucket is because you're applying force and accelerating the bucket. But in space, there is nothing 'accelerating' the rotation of a spacecraft , it is merely in continuous Newtonian motion...
  7. E

    Radius of centripetal force when on an angle.

    http://puu.sh/4IjIT.png I don't quite understand why this is correct. My initial try was this... (the only difference is at the end, bolded) r = 0.154m period = 0.426s rev per second = 1/0.426s w = 2*pi*(1/0.426) mg = Fn*cosx Fn = mg/cosx Fc = Fn*sinx = mg/cosx = mg*tanx...
  8. P

    Centripetal force problems for dynamics

    Centripetal force problems for dynamics :) Homework Statement I have two questions! 1. You are driving at a speed of 60.0km/h around a turn with a radius of 75m. The coefficient of friction between the tires and the road is 0.85. a. After traveling 20° around the turn, you hit a...
  9. X

    How is it possible that friction = centripetal force for turns?

    So, I am confused. If a car is driving on a flat surface and it turns, it experiences centripetal force. Apparently, the friction of the bike is equal to this force. This doesn't make sense to me. I've drawn a few forces on an example picture here: The car is going straight, and Fa is...
  10. X

    Physics turns and centripetal force on flat roads

    I am confused about this. I learned that the frictional force is pointing towards the center of the circle in circular motion (on a flat road) due to the tires. The thing is, I don't understand what the result of this friction is. The road is flat, and the motion of the car is straight...
  11. PsychonautQQ

    Inelastic Momentum / Centripetal force problem

    Homework Statement A small wooden block with mass .8kg is suspeded from the lower end of a light cord that is 1.6m long. The block is initially at rest. A bullet with mass 12g is fired at the block with a horizontal velocity vi. The bullet strikes the block and becomes embedded in it. After...
  12. O

    Calculating Centripetal Force for Circular Motion: Tips and Tricks

    Hello, I'm having trouble with solving for the centripetal force. Some questions in my textbook don't give the velocity and radius, so the centripetal force is a bit harder to calculate. There are three main scenarios which I am having trouble with: [1] A girl has a ball in her hand...
  13. K

    Centripetal Force of an amusement park ride

    Homework Statement In an amusement park ride, passengers stand inside an 8m radius cylinder. Initially, the cylinder rotates with its axis oriented along the vertical. After the cylinder has acquired sufficient speed, it tilts into a vertical plane, that is, the axis tilts into the horizontal...
  14. L

    Archived Centripetal force and Coriolis force?

    Homework Statement Suppose that you are on a rotating platform, going around with frequency w a distance r from the center. Suppose that you are watching an object that moves in a straight line. Produce an animation that shows the position of the object from your perspective. Does this...
  15. N

    Centrifugal and centripetal force

    There is a grass planted in a container which spins. Will the grass grow from the center of the container or will it bend towards the center. These are provided answers: This is a question in my book and there it is stated that it will bend towards the center(A answer) but it is not...
  16. adjacent

    Centripetal Force and radius of the circle

    When the radius of the circle decrease the object moves faster(With the same force) I believe this is a misconception .In common sense the object revolves around more,This leads us to think that it is moving fast but actually the object moves the same distance.Am I right?
  17. E

    Little confusion regarding centripetal force in vertical circle

    consider a pendulum. The mass 'm' is hung and now we are interested in finding the velocity so that it completes one circle. Clearly we can do it easily by conserving energy. Now my problem is with the top most point. Clearly the tension is minimum at this point so that string becomes slack...
  18. S

    Centripetal force carousel angle

    Hello everybody, i have got a question about the concept of centripetal force in general. Imagine a gondula of a carousel that has just started to rotate. Each gondula moves away from the center of the circular motion and forms an angle with the string. What would be the correct physical...
  19. A

    Finding centripetal force of an object

    this is a question i have to do over the holidays and have no clue of how to do it. i cannot access our school email in which i have the worked solutions to all the questions. A ball is tied to a string and whirled in a horizontal circle radius of 2.0m. The string makes an angle of 10...
  20. M

    Is tangential force the same as centripetal force?

    Homework Statement Rotor blades attatched to a disc rotate. The rotor blades rotate at a speed of 15574rpm. The blades are 220mm from the centre of the disc. These blades are attatched to a disc that is 400mm in diameter. A force of 8kN/rad acts upon the blades and 600N/rad. (see...
  21. O

    Centripetal force. Radius is not given. Find tension in each support

    There is this problem that I have been trying to do but I just cannot understand how to approach it. I have been doing centripetal problems for hours so maybe I am just tired. The thing is that I do not see an equation I can use to cancel out radius since the radius is not given. I have...
  22. G

    Centripetal force, enough information?

    Homework Statement We have a carousel that completes a revolution in 4,0 s. The radius of the carousel disk is 0,8 m and the length of the (massless) rope is 1m. A horsey or whatever weighing 1 kg is hanging from the rope. Can we from this information extract the velocity of the horsey...
  23. R

    Centripetal Force and Uniform Circular Acceleration

    I am in need for some help for a lab report. The issue has happened because there is a lab of 20 students that is being led by a recently retired NASA physicist trying to lead a team of graduate student (or camel jockeys as he puts it) and the lab instructions are being botched horribly...
  24. X

    Centripetal force, this is confusing. Why?

    Homework Statement Someone takes a rock and ties it to a string, and then starts swinging the rock around in a vertical circle. The centripetal force should be... Fc = Fg + FtIt's clear that the book sets Ft=0... but why? Can someone explain this?Homework Equations Fc = m * ac ac = v^2/rThe...
  25. T

    Centripetal Force Ball Swing Question

    Homework Statement An athlete swings a ball, connected to the end of a chain, in a horizontal circle. The athlete is able to rotate the ball at the rate of 8.16 rev/s when the length of the chain is 0.600 m. When he increases the length to 0.900 m, he is able to rotate the ball only 6.32...
  26. A

    Galileo and the centripetal force experienced by objects on the rotating earth

    Hi, This question is about a discussion in the two chief world systems, the second day about p 230 in the modern science library edition (around figures 10 and 11). I haven't found the excerpt online so I hope someone has the book. As an objection to a rotating earth, the claim that any...
  27. T

    Relationship between centripetal force and gravitational force of satelite

    In order for a satelite to achieve an orbit around the Earth the centripetal force of it needs to be exactly the same as the force of gravitation which is acting upon the satelite. Why is this so?
  28. C

    Centripetal Force - trying to find time

    Homework Statement A physicist is standing 10 feet from the center of a platform that can rotate about a vertical axis - the platform is horizontal. She is holding a weight that is hanging freely from a string. The platform starts rotating and eventually she notices that the weight is no...
  29. H

    Physics lab practical (Centripetal Force)

    physics lab practical! (Centripetal Force) Homework Statement I need help to come up with a lab to figure out the centripetal Force of a cork as it rolls down the ramp. Homework Equations Fc=(mv^2)/rThe Attempt at a Solution i know that Fc= (mv^2)/r ,but i don't know if the velocity in the...
  30. L

    Centripetal Force Minimum Period Question

    Homework Statement A boy ties a 3.00kg rock to a 0.70 m string and begins spinning it around in a horizontal circle at a constant speed. If the string will break if the tension is greater than 80.0 N, what is the minimum period for the rock to spinning in a circle. How do i solve this...
  31. N

    Centripetal Force and Roller Coasters

    Homework Statement A) A roller coaster has a vertical drop but followed by a loop. The total vertical height of the drop is 66m. It starts as a steep slope at an angle of 75 degrees relative to the horizontal and then enters into a circular path of radius R. In order to stay below 4 times the...
  32. S

    Centripetal Force - How to describe it?

    So I had a thought today, and I wanted to figure out if it's correct or not about centripetal force. I've always heard it described as the inward force something experiences as it goes around a curve. But could it better be described as the force necessary for an object to maintain circular...
  33. I

    What are the two equations for Centripetal Force

    Homework Statement I have to rearange both equations to find mass, radius, and velocity (each of them seperately). Homework Equations I know that Centripetal Force= mass x (velocty^2/radius). In this case velocity is also equal to 2∏r/T (where T is the period), so I subsituted that in for...
  34. B

    Centripetal Force vs Radius: Exploring Uniform Acceleration Lab Results

    During a lab, we had to plot graph between Centripetal Force vs Radius of rubber stopper (some uniform acceleration lab) the result i got was a horizontal line. Then a question asks Based on your graph of centripetal force vs. radius of rubber stopper's motion, can you conclude that centripetal...
  35. U

    Help Centripetal Force problem

    Here's the problem. I don't understand how to get the velocity? If you cannot read the attachment it reads: An amusement park ride consists of a rotating circular platform 8.26 m in diameter from which 10 kg seats are suspended at the end of 3.9 m massless chains. When the system...
  36. N

    Centripetal Force - Banked Curve

    Homework Statement A 1000kg car travels around a frictionless banked curve having a radius of 80m. If the banking is 20 degrees to the horizontal, at which specific speed must the car travel to maintain a constant radius? Homework Equations Fc = mv^2/r Fg(perp.) = mgcos(20) The...
  37. B

    Centripetal Force vs Centrifugal Force

    Hi, thank you for reading this topic. This is something that really bothers me...First of all let me say that I know what the terms centripetal and centrifugal stand for. What's the problem then? The problem is that I've always read that the centripetal force is an actual force and that...
  38. G

    Problems pertaining to centripetal force

    Homework Statement A golf ball with mass m = 0.05 kg is tied to a massless string of length L = 0.28 m. The ball is made to swing in a circle such that the string is horizontal throughout the motion. The ball makes one revolution every t = 2.1 s. m = 0.05 kg L = 0.28 m t = 2.1 s Homework...
  39. A

    Centripetal force vs period

    Homework Statement When plotting the centripetal force vs period graph, what goes on the x-axis and y-axis? I thought that since centripetal force does not depend on period, it goes on the x-axis, but now I'm not too sure. It also says plot Plot Fc as a function of T. Homework Equations The...
  40. V

    Vertical Centripetal Force to push an object

    I have this device, It has 3 masses 30 grams each (Red ones) the other masses are not considered. The masses are spinning at 600 rpm at that velocity this will reach maximun radius. The maximun radius the masses and reach due to the centripetal force is 15cm. Can this device push a 3kg mass at...
  41. L

    Discover the Influence of Horizontal Centripetal Force on Spinning Motion

    Imagine you are spinning a weight at the end of a string horizontally. As one increases the speed with which the weight is being spinned, the motion becomes more and more horizontal. I understand this occurs because the centripetal force (tension of the string) is increasing but at the same time...
  42. A

    How do you find centripetal force without knowing velocity?

    Homework Statement A tetherball goes around the pole at a constant velocity. The rope has a 2m length, makes a 30 degree angle below the horizon and the ball's mass is .5 kg. Homework Equations F(gravity)=m*a F(centripetal)=mv^2/r The Attempt at a Solution I'm stuck at trying to...
  43. M

    Centripetal force - Train on a curved track

    Centripetal force -- Train on a curved track Homework Statement You have a circular arc of railroad track to lay on the line from Dubuque to Albuquerque. The arc of track is 30º and the turn radius for the arc is 425 meters. It has to keep the path steady and secure for an ALP-46 locomotive...
  44. Feodalherren

    How Does Doubling Speed Affect Centripetal Force and Acceleration?

    Homework Statement A .2kg ball travels in a circle of r=1m, one revolution every second, what is the acceleration. What would happen to the force and acceleration if you double the speed?Homework Equations f=ma a= (v^2)/rThe Attempt at a Solution 2∏1m x ≈ 6.3m Speed of the ball = 6.3m/s a =...
  45. T

    Question about Centripetal Force

    So in a physics experiment, we used a motor to rotate a mass connected to a spring by a string and pulley until it's radius of rotation increased to a certain point. My question is, why did rotating it faster increase the radius of rotation? Centripetal force pulls objects inward, but the mass...
  46. M

    Spiral motion and the centripetal force

    Major brainfart here. Consider the spiral motion of a particle such that the distance from the origin to the particle is r(t) = e^t with a constant angular velocity. Now since the particle rotating with a constant angular velocity, I would think that the net force on the particle...
  47. N

    Centripetal Force required to hold electron

    Homework Statement An electron ( m = 9.11 * 10^-31 kg) moves in a circular orbit of radius 0.4 * 10^-10 m with an angular velocity of 2* 10^16 rad/s. Find the centripetal force required to hold the electron. Homework Equations This is one question from the chapter " Forces Due to...
  48. A

    Calculating Centripetal Force for Swinging Car Rear - 13.87 Feet Distance

    What is the Centripetal Force needed to swing the rear end of a car a distance of 13.87 feet? The car is a front wheel drive, 15 feet long and it weighs 2400 pounds. Presumably, the front end of the car maintained its straight uphill path with a grade of 7% traveling at 40 m/h? The road pavement...
  49. K

    Centripetal force experiment help

    i am confused.i need help with this experiment. experiment set up: http://img155.imageshack.us/img155/4027/20120428151358.png 1.measure total mass M of the crocodile clip and load.(in gram) 2.measure a length L of the string from the glass tube. 3.hold the tube vertically and whirl the rubber...
  50. J

    Centripetal Force Calc Question

    Homework Statement Calculate the centripetal force required to rotate a 3Kg object in a circle at a radius of 3m at one revolution per second? Ok for some reason i find circular motion a real struggle i have come up with an answer for this question but looking for some reassurance i am on...
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