What is Centripetal: Definition and 1000 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. D

    Circular Motion - Speed, Accel & Friction

    Homework Statement One of the most popular rides at carnivals is the one that resembles a large circular drum that rotates on its axis. Once the ride is spinning fast enough, the floor drops down and the riders are left pinned to the inside wall of the drum (I believe they are describing a...
  2. V

    Circular motion (approximation of centripetal acc.)

    Say I have a body moving in a circle of radius r with a constant velocity v. The time it takes the body to go around the circumference once is: T = 2πr/v Then the time it takes the body to go around a fourth of the circumference is T/4. Now, imagine a diagram where...
  3. R

    Simple Pendulum Centripetal Acceleration

    Homework Statement http://screensnapr.com/v/tC6gC3.jpg Homework Equations Im guessing: Centripetal Acceleration = v^2/r PE = mgh KE = .5mv^2 The Attempt at a Solution I tried to convert the givens into velocity by using .5mv^2, but that does not work.
  4. 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...
  5. Z

    Centripetal and Centrifugal Acceleration.

    I am a bit confused about these accelerations. Anything that rotates has a linear acceleration which is a vector in the same direction as linear velocity . There is also a centripetal acceleration which "pulls" wants to pull the objects towards the axis of rotation. So the sum of these two...
  6. 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...
  7. N

    Centripetal Force Lab: Exploring Frequency & Mass Effects

    Homework Statement Please go to: http://web.dsbn.edu.on.ca/~andre.huyzers/FOV1-000DC3EC/FOV1-000DC3EE/Lab%20Centripetal%20Force%20.pdf?Plugin=Loft Evaluation Question (E) Homework Equations The Attempt at a Solution Well I was thinking that as the frequency of revolution of...
  8. M

    Centripetal acceleration changing radians/s into rpm's

    Homework Statement Centrifugal castings- a copper sleeve of inner radius 2.10 cm and outer radius 2.20 cm is to be cast. To eliminate bubbles and give high structural integrity, the centripetal acceleration of each bit of metal should be 100g. What rate of rotation is required? State answer in...
  9. J

    What is the difference between centripetal and angular acceleration?

    So as the title says, what is the difference between centripetal and angular acceleration? I already know that there is a difference in the equations for each of the components but can someone please explain it conceptually? Please use some examples in your explanation.
  10. R

    Find the Centripetal Acceleration at 2.5m from a Rotating Platform

    Homework Statement A person is on a horizontal rotating platform at a distance of 4.3 m from its centre. This preson experiences a centripetal acceleration of 56m/s^2. What is the centripetal acceleration is experienced by another person who is at a distance of 2.5 m from the centre of the...
  11. E

    Circular motion and centripetal force

    Homework Statement A particle of mass m kg lies on the top of a smooth sphere of radius 2 m. The sphere is fixed on a horizontal table at P. The particle is slightly displaced and slides down the sphere. The particle leaves the sphere at B and strikes the table at Q. Find (i) the speed...
  12. A

    Grade 12 Centripetal Acceleration Question- Universal Law of Gravitation

    Homework Statement In the Bohr model of the hydrogen atom, the electron revolves around the nucleus. If the radius of the orbit is 5.8 z 10^-11 m and the electron makes 6.6 x 10^15 r/s, find; a) the acceleration of the electron b) the magnitude of the gravitational force of attraction...
  13. J

    COnstant centripetal force to move in a circle?

    An interesting thought just struck me and I wanted to confirm if it is correct. Do all objects (of fixed mass) need a particular magnitude of force to keep them moving in a circle, e.g: a ball will ALWAYS need a force of 10N to keep it moving in a circle If the speed increases then the radius...
  14. J

    Centripetal Force - maxium downforce for no skidding

    Homework Statement Downward force is used to keep a car in contact with the track. The motion through the air produces a force ppd to direction of travel pushing the car ONTO the track. A racing car of mass 720 kg takes an unbanked corner of radius 550 m at a speed of 50 m/s The max...
  15. B

    How Fast Should a Centrifuge Spin to Achieve Specific Acceleration?

    Homework Statement How fast (in rpm) must a centrifuge rotate if a particle 7.0 cm from the axis of rotation is to experience an acceleration of 1.2×10^5 g's? The Attempt at a Solution well first i made 7 cm .07 m. then i changed acceleration to 1.18x10^6 m/s^2 by multiplying 1.2x10^5 g's...
  16. I

    Centripetal force/motion experiment

    Homework Statement Hi, the aim of this experiment is the investigate the relationship between the centripetal force acting on an object moving in a circle of constant radius and its frequency of revolution. For the experiment, there is a rubber stopper attached to fishing line, that is...
  17. D

    Calculating g with centripetal acceleration

    Hi, I'm trying to find g, or 9.8 m/s^2, with the formula a = w^2 * r. First, I found the value for the angular velocity (2*pi/24 hours) and i converted this to radians per second finding the value 2*pi/86400. I googled the radius for the Earth and got 6,378,100 meters. Finally, i plugged these...
  18. J

    Calculating Centripetal Force for 6 kg Object

    Homework Statement Find the centripetal force required to rotate 6 kg object in a circle at a radius of 6m at one revolution per second. Homework Equations C.F. = mv2/r [b]3. The Attempt at a Solution [/b Circumference=2 pi r=2*3.14*6=37.68 C.F. = 6*(37.68)2/6=1419.78...
  19. S

    Calc Error in Centripetal Force | Physics Lab

    Homework Statement Determine the error in the calculated centripetal force, F (dynamic), for each value of r from the estimated error in the quantities m, r, and from the standard deviation from the mean of your three measurements of f. Derive the equation for the error using Rule # 2 for...
  20. K

    Centripetal and Centrifugal force

    I just read that Centrifugal Force is a false force. It does not exist. Inertia (which is not a force) is mistakenly called Centrifugal force. Now, here is my question According to Newton's 3rd law of motion, forces always exist in pairs; action and reaction. Centripetal force which is the...
  21. A

    Vertical Circular Motion involving centripetal force

    Homework Statement Say if you have water in the bucket and you spin it around really fast creating a vertically cricle. How come it won't fall on you when its at the top? Homework Equations The Attempt at a Solution
  22. P

    Ratio Problem Dealing with Radius and Centripetal Acceleration

    Homework Statement Two identical satellites orbit the Earth in stable orbits. One satellite orbits with a speed v at a distance r from the center of the earth. The second satellite travels at a speed that is less than v . At what distance from the center of the Earth does the second...
  23. P

    Centripetal Acceleration with Tarzan

    Homework Statement Tarzan plans to cross a gorge by swinging in an arc from a hanging vine, as shown in the figure. If his arms are capable of exerting a force of 1200 N on the vine, what is the maximum speed he can tolerate at the lowest point of his swing? His mass is 100 kg, and the vine...
  24. T

    Centripetal Force/Changing direction on ice - Turn length

    Homework Statement I am running to school at 6m/s when I hit a patch of icy sidealk. The coefficient of friction between the ice and my shoes is 0.16. I wish to turn my 55kg frame to the left. What is the smallest turn I can make? v = 6 m/s μ = 0.16 m = 55 kg Homework Equations Fnet = mv^2/r...
  25. N

    Centripetal force with Conservation of Mass

    1. Homework Statement : Essentially it is a loop with a ramp leading to it. Find the height h the car would start from in order to complete the loop. Also find the speed the car would have to be at to complete the loop Your answer should be in terms of r. No friction 2. Homework Equations : I...
  26. K

    Understanding Centripetal Force: How It Works in an Inertial Frame

    If the net sum of forces is zero , the object moves with constant velocity.(inertial frame) But , when this centripetal thing comes in Suppose we have only a force acting perpendicular to the motion of the body. then how does this centripetal force comes in , there are 4 fundamental forces...
  27. K

    Does Centripetal force cause a tangential force?

    If I have a string with a lump on the end and is being swung in a circle with a continuous angular velocity then I know that: F= m\frac{v^2}{r} or using angular velocity, F= m r \omega^2 But, is there a tangential force acting at the point of mass in its instantaneous direction, and if...
  28. 2

    Torque, mass has to be found with centripetal force

    Homework Statement A ball is tied to an elastic string of length 8.0m and swung in a horizontal circle with a velocity if 0.8m/s. When a metallic object is tied to a rope of length 2.75m and swung in a horizontal circle, it makes 1 revolution in 2.9s. The ratio of the centripetal force in the...
  29. K

    Simple(?) Speed bump and centripetal force problem

    Homework Statement A speed hump is installed. A 1800 kg car passes over it at 30km/h. The hump follows the arc of a circle with r=20.4 What force does the road exert on the car as the car passes the highest point of the hump? the answer is 1.15x10^4 N according to my professor and this random...
  30. J

    How would I calculate the centripetal acceleration of a car on an elliptical path?

    How would I calculate the centripetal acceleration of a car at any (every) point on an elliptical path? Assume the car's speedometer is showing a constant speed the entire time. Answer in terms of g forces, please. (And, I have never taken calculus). You could also assume zero g at...
  31. J

    Why does the centripetal force subtract from total force toward center?

    Text of the problem: Because the Earth rotates about its axis, a point on the equator experiences a centripetal acceleration of 0.033 7 m/s2, whereas a point at the poles experiences no centripetal acceleration. Assume the Earth is a uniform sphere and take g = 9.800 m/s2. (a) If a person at...
  32. G

    Centripetal Acceleration with distance

    Homework Statement You plan to throw stones by using a sling of length 0.7 m which you whirl over your head. Suppose you wish to throw a stone a distance of 36 m. What must be the centripetal acceleration of the stone just before its release if it is to reach this distance? Assume that the...
  33. D

    Proving Centripetal Acceleration - Lab

    Homework Statement This is from a lab. Part 1 of the Lab: We started out by hanging a spring vertically and attaching different weights to the spring. The mass of each weight along with the relative mass were given. Once the spring reached equilibrium, we measured the elongation and...
  34. B

    Maximum Centripetal Acceleration

    You are designing a centrifuge to spin at a rate of 13,810 rev/min. (a) Calculate the maximum centripetal acceleration that a test-tube sample held in the centrifuge arm 14.1 cm from the rotation axis must withstand. 249167 m/s2. (b) It takes 1 min, 16 s for the centrifuge to spin up to its...
  35. D

    Calculating Centripetal Acceleration in a Speed Skater's Turn

    Homework Statement A short track speed skaer is making a turn at one end an ice rink, increasing his speed frm uniformly 10 m/s t 20 m/s in two seconds. The radius of the turn is 5 meters. While he is in the middle of the turn, and mving at 15 m/s, what is a. tangential acceleration b...
  36. Seydlitz

    Question about Centripetal Force (How it could make object glued to the wall.)

    Homework Statement A man standing inside a cylinder rotating with a particular angular velocity ω could take his feet off the ground and stay 'glued' to the wall of the cylinder. Draw the free body diagram of the man. The Attempt at a Solution My question is how the gravitational force...
  37. E

    What Physics Principles Are Tested in NASA's 20-G Centrifuge Experiments?

    At its Ames Research Center, NASA uses its large “20-G” centrifuge to test the effects of very large accelerations (“hypergravity”) on test pilots and astronauts. In this device, an arm 8.84 m long rotates about one end in a horizontal plane, and the astronaut is strapped in at the other end...
  38. A

    Acceleration due to centripetal acceleration

    if there was acceleration toward the centre, then why doesn't the distance from the centre to the object reduce? what provides the equal and opposite counter force to centripetal force? (it's a pretty silly question, but i get confused)
  39. C

    Centripetal acceleration/ motion question

    I am trying to calculate the speed of an object at the point that it flys off the half circle ramp, and I was wondering if it would be correct to use the formula v2=v20+2aΔx to calculate the final velocity of the object as it exits the half circle thing.
  40. J

    How does centripetal force affects the path?

    When there's magnetic field, a charged particle moves in a circle. I would like to ask why won't the circle goes smaller even when there's a force pointing inward (towards the center of the circle). Thank you!
  41. P

    Can a Claw Design Hold a Spinning Ball Against Centripetal Force?

    Hi guys and gals, I have a robotics related engineering problem I need help with. So, for our robot we are building, it has a centripetal arm that launches a foam basketball. The arm is 2 foot in diameter rotating from the center with 3 pounds on each side (including projectile and...
  42. M

    Centripetal Force Lab Percent Error and Accepted Values Help PLEASE

    Hi! I need help and please do not delete this! What I need help with i cannot put into the template provided. I am sorry but I need help with a lab report. PLEASE I AM BEGGING YOU TO NOT DELETE THIS BECAUSE IT DOES NOT FOLLOW THE TEMPLATE! I REALLY REALLY NEED HELP! I need to find the...
  43. C

    Understanding Centripetal Force: Exploring Gravity and Planetary Motion

    This might be silly question for some people, yet better to ask than don't know the answer :(. so the thing is , i know that centripetal force holds a thing to keep running on a path, but when i think of Earth and all those planet which surround it, the centripetal force is gravity right ? and...
  44. I

    Centripetal force carnival ride question

    Homework Statement Riders in a carnival ride stand with their backs against the wall of a circular room of diameter 8m. The room is spinning horizontally about an axis through its center at a rate of 45 rev/ min when the floor drops so that it no longer provides any support for the riders...
  45. G

    Centripetal force discussion question (Washing machine).

    Note: This discussion question is from my University Textbook, as it so happens you can only get the solutions to half of the odd numbered exercise questions... Disclaimer: I have been trying to wrap my head around this answer for a good 5 hours now, so it's not like I'm coming here to be...
  46. A

    Centripetal Force + Law of conservation of energy question.

    Homework Statement Your favourite physics teacher who is late for class attempts to swing from the roof of a 24-m high building to the bottom of an identical building using a 24m rope as shown in Figure 5. She starts from rest with the rope horizontal, but the rope will break if the tension...
  47. S

    Using centripetal force, determine the acceleration of gravity

    Homework Statement This question relates centripetal acceleration and gravity. The general question is to determine the acceleration of gravity using centripetal force. A coin is tied to a string and swung in a circle over a person’s head. There is also a plastic tube attached to the string...
  48. E

    Centripetal Acceleration/Rotational Motion HW Problem

    A block sits at the top of a smooth sphere of radius 1m. Suddenly, under the force of gravity, It begins to slide down the surface of the sphere until it leaves the surface. At what speed does it leave the surface? mgcosθ + N = mv^2/R But N =0 v^2 = Rgcosθ V^2 = gcosθ speed = v = (...
  49. S

    Simple centripetal force question

    I think the force of friction should act to the left, toward the rotational axis. My physics teacher says that the force of friction is acting out of the page, so I am confused. Thanks!
  50. S

    Exploring Centripetal Force in Planetary Motion

    Hi, I know that centripetal force for planetary motion is the same as the force of gravity between that satellite and planet. For example (I know these numbers may be completely unrealistic but just for the sake of easy calculation...) if the mass of the Earth is 1x10^30 kg and the mass of...
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