Centripetal Definition and 1000 Threads

Homework Statement How much force is needed to swing a 4kg mass in a 3m radius horizontal circle so that each cycle takes exactly 2 seconds. Answer is 118N but the problem is how do I get to that... Homework Equations V=2Pir/T F=mv^2/r The Attempt at a Solution I tried...

Homework Statement What is the Shape of graph that represents Centripetal acceleration as a function of time? Homework Equations The Attempt at a Solution I know its a parabola, but am not sure how the curve is going to look.

in physics, I've been taught that centripetal acceleration is given by v^2/r, but when i try to derive it myself, i get a=2v^2/(pi*r). i said that if the time period is T, after a time of T/4, the velocity would be going in the next direction, i said west to south, and this gives the equation...

Homework Statement Given a Ferris wheel that rotates 5 times each minute and has a diameter of 19 m, with the acceleration of gravity as 9.8 m/s^2, what is the centripetal acceleration of a rider? Answer in units of m/s^2. (There's a diagram that shows a ferris wheel with radius 9.5 m spinning...

"A plumb bob does not hang exactly along a line directed to the centre of the Earth's rotation. How much does the plumb bob deviate from a radial line at 35 degrees north latitude? Assume the Earth is spherical." I found the radius of the Earth and rotational velocity at the equator via...

Homework Statement what is the magnitude and direction of the centripetal acceleration necessary to confine the motion of a 0.5kg mass moving at speed 0.1m/s to a circular path 0.2m in radius Homework Equations a = v^2/r The Attempt at a Solution 0.1^2/0.2 = a a =...

Homework Statement A small ball with a mass of 3.0kg revolves uniformly in a circle on a frictionless horizontal surface. The ball is attached to a string of 1.40m to a pin set at center of circle. The object makes 2rev/sec. a)find the centripetal accel b)find the tension exerted on the...

Homework Statement http://img.skitch.com/20091201-pxecs3d574itggpejybhdbp3qr.jpg Essentially, as an experiment, our physics class whirled a stopper attached to a string that went through a tube that was finally attached to a weight on the bottom of the string. The Attempt at a Solution...

Homework Statement In the Bohr model of the hydrogen atom, the electron revolves around the nucleus. If the radious of the orbit is 5.3x10^-11 m and the electron makes 6.6^13 r/s find a)the acceleration of the electron and b)the centripetal force acting on the electron. (this force is due...

Homework Statement A body can move in a circle at a constant speed if a. there is an unbalanced radial force directed inwards. b. inward and outward forces are equal in magnitude c. the net radial forces equal the net tangential forces d. all the statements above are correct e. none of...

Homework Statement We had an experiment where you have two masses on either side of a string and you swing one in a circle,while the other hangs vertically down(providing Fg). "When you swing the mass in a circle, your hand most likely moved in a small circle. What effect does this have on...

Homework Statement A ball of mass M is attached to a string of length R and negligible mass. The ball moves clockwise in a vertical circle. When the ball is at point P, the string is horizontal. point Q is at the bottom of the circle and point Z is at the top of the circle. Air resistance is...

I'm having trouble with circular motion, for the simple reason that my instructor taught it differently than my book explains and how I see it done online. He explains that centripetal force moves towards the outside of the circle, and is an independent force. Meaning, he explains it as a force...

Sorry if this is posted in the wrong area, I am relatively new. Circular Motion Lab is set up like this to study circular motion...

What is the relationship between the mass and velocity of a whirling object? base of graph relationship What is the relationship between the radius of revolution and the velocity of a whirling object? What is the relationship between the velocity of a whirling object and the centripetal...

w=2π /T v=rw=2πr/T a=rw2=r(4π2r2/T) This I know, but why can't I just differentiate v with respect to t to get a? (But the answer is wrong) Can anyone tell me why? Thanks.

Homework Statement A 1000 kg car is traveling along a flat section of the highway at a speed of 90.0 km/h. The driver notices a curve in the road ahead, with a radius of 150 m. a) If the pavement is dry and the coefficient of friction between the car tires and the road is 0.820, determine...

Homework Statement An object weighs 100N at the South Pole. How much does it weigh at the equator? Given: Earth's rotational spin speed 465m/s Diameter of the Earth is 1.274 x 10^7 m Homework Equations Fc = m x v^2 / r The Attempt at a Solution Well I have this general...

I'm doing a project on being able to create Earth like conditions in space. Basically its artificial gravity on space stations. I have a few thoughts and I just need to know if they're right so I don't go wandering a long a path and find out its the wrong one! I'm mostly using the concept...

1. Suppose a space shuttle is in orbit 400 km from the Earth's surface, and circles the eart about once every 90 minutes. Find the centripetal acceleration of the space shuttle in its orbit. Express your answer in terms of g, the gravitational acceleration at the Earth's surface. 2...

Homework Statement Hi I have a question that involves a laundry dryer, and it must turn at a certain velocity to so that when the object hits 68 degrees to the horizontal it will fall. the radius is the only given r = .330m Homework Equations the answer is stated as Fc = N +...

This is probably a geometry question more that a physics question. I am trying to prove that in uniform circular motion \Delta V/V= s/R. I am basically trying to show that S forms a right triangle with \DeltaV, when V{1} is added to V{2} as a vector. (This is to demonstrate that the triangles...

Homework Statement A model airplane whose mass is 875 grams flies in a horizontal circle of radius 3.46 m at the end of a string which is at an angle 10.5 degrees below the horizontal. Find: a) the tension in the string b) the speed of the airplane Homework Equations Fc=T=mv^2/r...

Homework Statement How do I find the direction of the centripetal force and acceleration? Homework Equations mv^2/r - centripetal force v^2/r - centripetal acceleration The Attempt at a Solution Would it be inward or outward the radius?

A car rounds a corner of radius r= 45 m. If the coefficient of static friction between the car and the road is= 0.82, what is the greatest speed the car can have in the corner without skidding? am i in the right direction with v^2=.82*9.8*45m? then square root both sides for the answer?

A windmill starts from rest and rotates with a constant angular acceleration of 0.25 rad/s2. How many seconds after starting will the magnitude of the tangential acceleration of the tip of a blade equal the magnitude of the centripetal acceleration at the same point? I don't exactly know...

Homework Statement Consider a conical pendulum that consists of a bob on one end of a string of negligible mass with the other end of the string attached to a point on the ceiling, as shown. Given the proper push, this pendulum can swing in a circle at a given angle, maintaining the same...

#1) A child ties a .25kg rock to the end of a string and whirls it at a constant speed in a horizontal circle of radius 75 cm. What, approximately, is the maximum speed at which the stone may be whirled if the string will break for a tension exceeding 300N? A. 10 m/s B. 13 m/s C. 15...

If I swing around a mass attached to a string, and then suddenly let go, the mass will fly off in a direction tangent to the circle it was swinging around. My question is, what will happen to the string? I know it will follow the mass on its tangental path, but how do we explain the behavior of...

Suppose a nickel sits on a flat turntable that spins at 78 rpm (revolutions per minute) while sitting on a horizontal surface. The nickel is 15 cm from the center of the turntable. What is the minimum coefficient of friction that keeps the nickel on the turntable? Relevant equations: I am...

Homework Statement This will be kind of long because it's not just a simple problem, it's a lab. Sorry about that. So the lab is testing the concepts of forces and centripetal force, for starters. We are supposed to be "investigating the relationship between period and acceleration." In class...

Homework Statement A swing ride at a carnival consist of chairs that are swung in a circle by 15.0 meter cable that makes a 60 degree angle with a verticle pole. The mass of the chair and the occupant is 179 kg. Determine the tension in the cable. Find the speed of the chair Homework...

Homework Statement Hi guys, i need some help solving the following question. An Airplane is flying in a Horizontal circle at speed of 620km/h. If the wings of the plane are tilted 35 degrees to the horizontal, what is the radius of the circle in which the plane is flying? Assume that the...

Two cars are traveling at the same speed of 28 m/s on a curve that has a radius of 124 m. Car A has a mass of 1080 kg, and car B has a mass of 1500 kg. Find (a) the magnitude of the centripetal acceleration and (b) the magnitude of the centripetal force for Car A, (c) the magnitude of the...

A centrifuge is a device in which a small container of material is rotated at a high speed on a circular path. Such a device is used in medical laboratories, for instance, to cause the more dense red blood cells to settle through the less dense blood serum and collect at the bottom of the...

1. Homework Statement : A 4.00 kg object is attached to a vertical rod by two strings (as below). The object rotates in a horizontal circle at constant speed 6.00 m/s. mass = 4.00 kg V = 6.00 m/s Homework Equations centripetal acceleration = Ac Ac = V^2/r...

Homework Statement hi guys i need help solvign the following problem. A mass 1kg on a frictionless table is attached to a hanging mass 4kg by a cord through a hole in the table. Find the frequency with which 1KG mass must move for 4kg to stay at rest, if the radius of the circle is 75m...

Homework Statement a. Draw a free body diagram for mass Mb while in motion (fig. 2a). Identify the centripetal force. assume that the mass hangs vertically b. Calculate the magnitude of the force exerted by the spring on mass Mb = 402g, moving in a circle of radius r=18cm (fig. 2a). The...

For starters, I feel sorry for those who have to sift through all these questions and answer them. It seems like you've got a very busy job! Hopefully there are many of you to share the workload. This is an assignment question that I get 3 attempts on. I've made two, both were incorrect...

can centripetal and centrigugal force act together?

Moment of inertia, I is the resistance of an object to rotational motion. It is the rotational analogue of mass and is given by the following integral, I = \intmiri2 . A simple derivation was explained to me as follows. A moment, τ is the product of force, F and lever arm, r. τ = F*r...

I have my own concept question. Ignoring air friction and mass of string, and only considering the motion of the bottom right quarter of a circle, where only gravity acts on the mass. Lets say I have a mass attached to a rope with length R. I hold the string in my left hand and the mass...

Homework Statement Pulsars are neutron stars that emit X rays and other radiation in such a way that we on Earth receive pulses of radiation from pulsars at regular intervals equal to the period that they rotate. A certain pulsar has a period currently of length 33.085m/s and is estimated to...

Homework Statement A roller-coaster vehicle has a mass of 510 kg when fully loaded with passengers (Fig. P7.28). http://www.webassign.net/sf/p7_28.gif (b) What is the maximum speed the vehicle can have at point B in order for gravity to hold it on the track? Homework Equations...

Homework Statement Consider the rear view of a bus turning right. If the driver turned the bus while traveling too fast, the bus could topple over. If the bus did topple would the bus fall to the left or to the right? Explain. Since the bus was turning to the right, the centripetal force...

Homework Statement An airplane is flying in a horizontal circle at a speed of 460 km/h (Fig. 6-42). If its wings are tilted at angle θ = 37° to the horizontal, what is the radius of the circle in which the plane is flying? Assume that the required force is provided entirely by an...

Homework Statement A skater holds her arms outstretched as she spins at 225 rpm. What is the speed of her hands if they are 152 cm apart? The Attempt at a Solution I converted 225 rpm to 3.57 rps and found the angular velocity (23.56 rad/s) to plug into the equation v=wr, but it didn't...

Homework Statement A) An amusement park ride consists of a rotating circular platform 10.8 m in diameter from which 10 kg seats are suspended at the end of 2.34 m massless chains. When the system rotates, the chains make an angle of 29.4◦ with the vertical...

Homework Statement An old streetcar rounds a flat corner of radius 9.1 m, at 16 km/h. What angle with the vertical will be made by the loosely hanging hand straps? Homework Equations The equations I know: acceleration = velocity squared / radius (a = v^2 / R) Force = mass *...

Hi, thanks in advance for any help and info. Have two conditions. The first condition is a mass of water spinning as a fixed mass. Say we have a rectangular mass .25 inches tall, 2 inches long and .50 thick spinning at 3000 RPM with its center of mass at R = 2.00 inches. (Please see first...