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. 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...
  2. S

    Hard centripetal forc eproblem

    Homework Statement a 1000kg car negotiates a banked friction free track or radius 25m with speed 30m/s to what angle to the horizontal is the road banked? Homework Equations The Attempt at a Solution tried to calculate the normal force of the car, to find the angle between the...
  3. S

    Centripetal Acceleration on an Inclined Plane

    During revision for an exam I have tomorrow I came across a question that left me confused, and I wasn't entirely satisfied with my teacher's explanation today. I'm worried something of the sort may come up in the exam and I won't be entirely certain how to deal with it. We have a plane...
  4. 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?
  5. S

    Orbits of the planets and centripetal acceleration

    [b]1. The table below lists the average distance from each planet to the Sun and the time each planet takes to make a complete orbit around the Sun (“Orbital period”). The orbits of all of the planets are roughly circular. Your job is to determine a relationship between the radius r of a...
  6. F

    Centripetal accelerations with two parallel axes - the Scrambler

    Centripetal accelerations with two parallel axes -- the "Scrambler" Homework Statement This should be a pretty quick and straightforward question to answer. The problem regards centripetal forces on an object rotating simultaneously around two parallel axes, like in the "Scrambler" amusement...
  7. D

    Centripetal force or escape velocity?

    Homework Statement A certain spherical planet which is not rotating has a radius of 6.36 x 105 m and a mass of 1.89 x 1021 kg. At what minimum speed would a vehicle traveling along its surface just begin to leave the ground? Homework Equations FC = mv2/r FG = GMm/d The Attempt at a...
  8. D

    What is the minimum radius for safe circular flight?

    Homework Statement An airplane is flying in a horizontal circle at a speed of 141 m/s. The 94.2 kg pilot does not want his radial acceleration to exceed 8.88g What is the minimum radius of the circular path? Homework Equations v^2/r The Attempt at a Solution 141^2/.00888 kg
  9. D

    Centripetal Force: Find Min Radius of Airplane Path

    Homework Statement An Airplane is flying ina horizontal circle at a speed of 141 m/s. The 94.2 Kg pilot does not want his radial acceleration to exceed 8.88 g. What is the minimum radius of the circular path? Homework Equations v^2/r Fnet = M x A The Attempt at a Solution 141^2 / .00888 kg?
  10. D

    Centripetal acceleration on Earth

    Homework Statement An object orbits the Earth at a constant speed in a circle of radius 6.38 x 106 m, very close to but not touching the Earth's surface. What is its centripetal acceleration? Homework Equations a = v2/r = 4\pi2v/T2 v = 2\pir/T The Attempt at a Solution I plugged in...
  11. P

    Centripetal Acceleration at Equator

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  12. P

    What is the centripetal force acting on a truck going around a circular path?

    Homework Statement A truck with a mass of 20000kg goes around a circular path with a speed of 50km/hr. If the radius is 105m. Calculate the centripetal force acting on the car. Homework Equations This is why I can't get the answer to this question. I don't know which equation to use. I'm...
  13. W

    How Massive Must a Neutron Star Be to Keep Its Surface Intact While Rotating?

    certain neutron stars rotate at about 1.0 revolutions per second. If such a star has a raduis of 20km, what minimum mass must it have so that material on its surface doesn't fly off during the rapid rotation? ive tried working out the centripetal acceleration, being 7.89 X10^8 then subbed...
  14. Y

    Relativistic centripetal force

    Looking on the internet, it seems to very difficult to find a simple straightforward statement of the equations for relativistic centripetal force. This is my point of view and hopefully with some feedback we can come to a consensus. Consider a test mass moving in a circle with radius r. The...
  15. X

    Centripetal Force and Tangential Velocity

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  16. R

    Centripetal acceleration of a satellite orbiting Earth

    Homework Statement A satellite is orbiting the Earth in a stable orbit of which the radius is twice that of the Earth. Find the ratio of the satellites cepripetal acceleration to g on the Earth's surface. Homework Equations centripetal acceleration = (v^2)/r or (4rpi^2)/T^2 The...
  17. G

    Centripetal Force: At what RPM must you gainer at to decapitate yourself?

    Ok, here's a question I've been worrying about recently: If you were to be rotated about your waist, at what rotational rate would your body begin to tear apart, specifically decapitation? Basically, I've been doing lots of gainers (running back-flips) and I'm concerned that if I get...
  18. M

    Tension and centripetal forces

    Homework Statement A stone of mass 4 Kg is attached to a string , its length 10 m .it moves in a horizontal circular path. The tension force of the string becomes 160 N then calculate its velocity. The Attempt at a Solution Its quite easy to solve when supposing the tension force =...
  19. S

    Why doesn't centripetal force change the magnitude of speed

    Hello guys, It is hard for me to explain my question so I'll use a diagram Consider plane velocity - As centripetal force Wind velocity- As the velocity of object at the start R- As the resultant velocity So in the centripetal force objects this resultant velocity seems constant...
  20. M

    Velocity given centripetal force, accounting for friction

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  21. G

    Angular, linear velocity & centripetal acceleration

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  22. S

    Centripetal force problem ( not enough givens?)

    Hey guys, I could not understand this question. There weren't enough givens for myself to understand how to get the period. 1. Earth and the Moon are separated at their centres by a distance of 3.4x10^8m. Determine the period of the Moon's rotation about Earth. 2. mv^2/r=Fc 3. I...
  23. S

    How Does Friction Provide Centripetal Force During a Car Turn?

    Hello guys, I wasn't interested in these stuff those days and I never got it. Now when you do a car turn the friction from the tires provide the centripetal force right. I have few quick questions. How does the friction from tires give a force in the centripetal direction, how come it...
  24. K

    Understanding the Units and Origin of a Velocity^2 vs. Centripetal Force Plot

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  25. B

    Calculating Mass for Centripetal Force at 100 km/h Speed with 350 m Radius Curve

    A 2.4 x 103 N force is necessary to keep a car and driver moving at a speed of 100 km/h through the middle of a highway curve that has a radius of 350 m. What is the mass of the car and driver? Im really confused on this question, I was told the formula should be something like FC=MV^2...
  26. A

    Centripetal Acceleration & Frictional Force

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  27. R

    Centripetal Force Lab of string and mass

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  28. O

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  29. F

    A question about centripetal acceleration

    http://img517.imageshack.us/img517/4817/aholelol.png http://img532.imageshack.us/img532/881/bridgelol.png There are 2 images. Let ac be the centripetal acceleration vector and v the speed vector. Now are my drawing right or have I gotten this whole thing wrong? My teacher said that the...
  30. S

    Centripetal Force Homework: Total Energy, Speed, Tension & Distance

    Homework Statement A 0.10 kilogram solid rubber ball is attached to the end of an 0.0 meter length of light thread. The ball is swung in a vertical circle. point P, the lowest point of the circle, is 0.20 meter above the floor. The speed of the ball at the top of the circle is 6.0 meters per...
  31. H

    Calculating Centripetal Acceleration Angle for a Race Car on a Circular Track

    Homework Statement A race car starts from rest on a circular track. The car increases its speed at a constant rate at as it goes 2.25 times around the track. Find the angle that the total acceleration of the car makes with the radius connecting the center of the track and the car at the moment...
  32. E

    Centripetal force exerted on Earth

    Here is the problem and the choices: Calculate the centripetal force exerted on the Earth by the Sun. Assume that the period of revolution for the Earth is 365.25 days, the average distance is 1.5 × 10^8 km and the Earth’s mass is 6 × 10^24 kg. The choices are: 1. 3.56775 × 10^22 N 2...
  33. P

    Centripetal Motion on a Semi-Rollercoaster

    http://cache.rcdb.com/pictures/picmax/p5740.jpg I am doing an analysis on a roller coaster that is represented on the diagram attached. However, I am having trouble analysing the curve. The radius is 36.9m and it is 160km/hr going up and then it free falls back down from 115m for about three...
  34. H

    Centripetal acceleration v^2/r?

    can someone justify why centripetal acceleration = v^2/r? And I'm not asking about algebraic proof.
  35. C

    Centripetal Force: Candle Flame in Vacuum

    so when we light 2 candles and put them on the edge of a bike tire and we spin the bike tire the candle flames lean in towards the center. And we put a glass chimney around the candles to protect the flames but the top is open . like seen here around the 4.5 minute mark in this video. . I...
  36. J

    Centripetal forces effect on weight

    So I am building this program for fun. I thought I would combine some different elements of basic physics into it. I am letting people place in numbers to create a custom planet (radius, gravitational acceleration, rotation speed (tangential velocity?). Anyway, I ran into an issue. I want...
  37. M

    Calculating Normal Force on a Roller-Coaster Car Over a Circular Hill

    1. A roller-coaster car has a mass of 1290 kg when fully loaded with passengers. As the car passes over the top of a circular hill of radius 20 m, its speed is not changing. (a) At the top of the hill, what is the normal force (using the negative sign for the downward direction) FN on the car...
  38. M

    How Can I Prove the Centripetal Force Equation f=mrw^2 Using Experiments?

    Hi there, sorry if this is not in the right section, but i have to do an investigation, i have chosen to prove f=mrw2. I will be using a rotational air table, and this the handheld whirly string and mass experiment - sorry to be vague. basically i am not the best physicist so i would very much...
  39. O

    Centripetal force on a top down loop

    Homework Statement A special electronic sensor is embedded in the seat of a car that takes riders around a circular loop-the-loop at an amusement park. The sensor measures the magnitude of the normal force that the seat exerts on a rider. The loop-the-loop ride is in the vertical plane and...
  40. M

    Deduction of centripetal force

    I have questions about the deduction of law of centripetal force http://img42.imageshack.us/img42/5841/centripetalforce.gif Why do we assume that the change in direction of velocity of the object is V(t+dt) And similarly the change in direction of radius? Also what is the triangle of...
  41. M

    Using centripetal force to fight lenz?

    hello to all, first post on this side of the web, maybe some of you folks can give me an opinion on something I've been running in my head ok, so this stemmed from thinking about how to overcome lenz law with gravity i thought of a magnet on the end of a lever, with a free standing...
  42. GRB 080319B

    Centripetal Force: Rotating mass

    Mass on a string undergoing uniform circular motion by hand: I was taught that the centripetal force F = mV^2/R is a resultant force, and in this case was due to the tension force by the wire on the mass. I am trying to understand what is causing the tension and what causes the string to break...
  43. J

    Confused about Centripetal and Radial Acceleration

    Hello, I was trying to do this problem and then I looked at the solution manual and found something that confused me. I am having trouble distinguishing between centripetal and radial acceleration. According to the equation in the book a_r=-a_c, which kind of confuses me. Isn't a centripetal...
  44. D

    Centrifuge - find centripetal acceleration

    Homework Statement You are designing a centrifuge to spin at a rate of 15,300 rev/min. (a) Calculate the maximum centripetal acceleration that a test-tube sample held in the centrifuge arm 14.7 cm from the rotation axis must withstand. 377361.36 m/s2 (b) It takes 1 min, 16 s for the...
  45. M

    Centripetal force of a rotating ride thing

    Just had a question in an exam asking me to find the centripetal force of a capsule on a ride like this: It gave the mass of a capsule, its velocity and radius etc. Would I have had to multiply by the number of capsules, because it did state the number. I didn't do this, but someone told me...
  46. M

    Why does an object have constant speed with Centripetal Force

    Hi, I understand how centripetal force works and all. But I still don't understand, when looking at a satellite orbiting the Earth, the only force acting is its weight, which is in the direction of the Earth. How does its circular motion start in the first place? If the only force there is is...
  47. M

    Centripetal acceleration at equator

    The centripetal acceleration of a person standing at the equator is about 0.03 m s–2. (Radius of the Earth = 6.4 × 106 m.) The size of the force R provides a measure of the apparent strength of the gravitational field. Show that the apparent field strength g at the equator differs from...
  48. M

    Centripetal force in London Eye

    The centripetal force is caused by: Friction between seat & person or push of capsule wall on person. How come the answer is not the Tension in the cable?
  49. M

    How Far Can a Spider Safely Cling to a Spinning Ceiling Fan Blade?

    A ceiling fan is turning at a rate of 100 revolutions per minute. A spider is clinging to a blade. If he experiences a centripetal acc greater than 0.3g, he wil lose his grip and be flung off. How far from the centre can he safely go? I used: T = 60/100 = 0.6 angular velocity = 2pi/T =...
  50. J

    Having trouble with a centripetal force problem

    Homework Statement A 2.0 kg stone is whirled in a horizontal circle on the end of a 2.1 m long rope. The stone travels around the circle 50 times each minute. What centripetal force is exerted by the rope on the stone? Homework Equations The Attempt at a Solution I've tried to...
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