Circular motion Definition and 1000 Threads

Homework Statement A toy airplane is tied to the ceiling with a string. When the airplane's motor is started, it moves with a constant speed of 1.01 m/s in a horizontal circle, as illustrated in the figure. If the angle the string makes with the vertical is 38°, and the tension of the string...

The asteroid 243 Ida has a mass of about 4.0×1016 and an average radius of about 16 (it’s not spherical, but you can assume it is). A)Calculate the speed with which you would have to throw a rock to put it into orbit around the asteroid 243 Ida, near the surface. v= ? B)How long would...

1. At a distance of 25km from the eye of a hurricane, the wind is moving at 180km/h in a circle. What is the magnitude of the centripetal acceleration, in meters per second squared, of the particles that make up the wind? Homework Equations Ac=V^2/r = 4∏^2r/T^2 = 4∏^2rf^2 The Attempt...

Homework Statement What is the acceleration (in m/s^2) of a 10 kg mass moving with speed 2 m/s in uniform circular motion about a circle of radius 2m? Homework Equations F=ma a=v^2/r in uniform circular motion The Attempt at a Solution Seems simple enough. To find the...

Homework Statement At takeoff, a commercial jet has a speed of 60.0 m/s. Its tires have a diameter of 0.850 m. (a) At how many rpm are the tires rotating? (b) What is the centripetal acceleration at the edge of the tire? (c) With what force must a determined 10-15 kg bacterium cling...

Homework Statement car travels in a flat circle of radius r. at certain point instantaeous velocity is 24 m/s west and the total acceleration is 2.5 m/s2 53 degrees north of west. find radial and tangential acceleration. and periodHomework Equations ar= 2.5cos37 at=2.5sin37 r=24 x 24/ar T=...

Homework Statement You swing a 6.5 kg bucket of water in a vertical circle of radius 3.6 m. What speed must the bucket have if it is to complete the circle without spilling any water? mass=6.5 kg r= 3.6 Homework Equations ay=(v^(2)/(r)) may= A-N-Mg The Attempt at a Solution I know...

The coefficient of static friction between the slider and the rod is u=0.2. The inclined rod rotates about a vertical axis AB with a constant angular speed, w, as shown in Figure. At the instant shown, the slider is positioned at 0.6 m from B. (i) What is the acceleration of slider P if it does...

while using equations of circular motion why do we need to express all angles in radians?

How is tangential accleration zero in uniform circular motion?? Homework Statement the magnitude of tangential velocity is same but the directions are different..so how can the tangential acceleration be zero?? Homework Equations The Attempt at a Solution

Alright, I have wondered this for a very long time and probably thought about it for longer than I should have but the more I think about it, the more I seem to be correct and the more frustrating it is to talk to people about it... Anyways, I'm sure everyone has heard of the saying "lefty...

Homework Statement [PLAIN]http://img687.imageshack.us/img687/5055/imagelrl.jpg Homework Equations Static friction = (9.81sin60 x 0.2)N Centripetal force = mr(w)² The Attempt at a Solution I am only abl to get part (i), need hints for part (ii) and (iii). Thanks in advanced

A special electronic sensor is embedded in the seat of a car that takes riders around a circular loop-the-loop ride 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 its radius is 21 m...

Lewis is a trapeze artist. He is hanging upside down on a swing bar; he is holding on to the swing bar with his knees. Lewis is holding his partner Amanda below him, who weighs 475 Newtons. Assume that Amanda moves on a circle that has a radius of 6.50 meters. At a swinging speed of 4.00 m/s...

The Earth rotates once per day about an axis passing through the north and south poles, an axis that is perpendicular to the plane of the equator. Assuming the Earth is a sphere with a radius of 6.38 x 106 m, determine the speed and centripetal acceleration of a person situated at a latitude of...

Homework Statement A charged particle (mass m, charge q) is moving with constant speed v. A magnetic field \vec{B} is perpendicular to the velocity of the particle. Find the strength of the field required to hold the particle on a circular orbit of radius R. Homework Equations \vec{F} =...

Hello! I have a problem which is solvable using simpler methods, but I'm trying to use it as a bridge to understanding how to do these problems in a more rigorous setting. Homework Statement A train slows down as it rounds a sharp horizontal turn, slowing from 90 km/hr to 50 km/hr in the...

Homework Statement One end of a string is attached to a mass of 7.5kg which is at rest on a horizontal table, coeffecient of friction being = 1/3. String passes through a small hole in the table and supports at its other end a mass of 2.5kg which is revolving in a horizontal of radius 20cm...

Homework Statement A 915kg car goes over a hill. If the radius of this curve is 43m, how fast must the car travel so that it exerts no force on the road at the crest. Homework Equations Fc = mv^2/r Fg = mg The Attempt at a Solution Fc = Fn+Fg Fn=Fg Fg=mg =(915)(9.81)...

Keys with a combined mass of 0.100 kg are attached to a 0.25m long string and swung in a circle in the vertical plane. a) What is the slowest speed that the keys can swing and still maintain a circular path? b) What is the tension in the string at the bottom of the circle? for part a, I...

Homework Statement An astronaut is standing in an space station that spins. The linear speed and the centripedal aceleration that he experiences are bigger on his feet than on his head. Scientific experiments have proved that a difference of (1/100 )g won't produce this inconveniet for...

I am learning uniform circular motion and the question says: A child on a sled comes flying over the crest of a small hill. His sled does not leave the ground but he feels the normal force between his chest and the sled decrease as he goes over the hill. Explain. Now, I know that normal force...

Dear physicists I am a physics teacher in London. Whilst I can understand exam style questions on circular motion (you would hope so !) I do have something which is bugging me. It is regarding an object completing a "loop-the-loop" inside a track. (like a roller coaster, but let's keep...

You throw a Frisbee to your friend. The Frisbee has a diameter of 28.0cm and makes one turn in 0.110s. What is the centripetal acceleration at its outer edge? ac=4π2r/T2 I actually know the answer and how to solve this question... ac=4π2r/T2 ac=π2(0.14m)/(.100s)2 = 4.57 x 102 m/s2 My question...

Homework Statement I don't want anyone to do it for me i am just sortof stuck any hints would be good. OK so an object is spinning and its mass is x it's path has a radius of z, it is swinging in the vertical plane. What is the slowest it may be swung while maintaining the circular motion...

I always see them in my dynamics problem but I never understand what are they used for, typically? Just to get some sort of perspective on the thing. It's supposed to be a rod connected to two pistons moving with linear and circular motion...

An Earth satellite moves in a circular orbit 589 km above Earth's surface with a period of 96.26 min. What are (a) the speed and (b) the magnitude of the centripetal acceleration of the satellite? I know I need the equations for 1) period and 2) centripetal acceleration and 3) r. 1) T=...

A smooth wire forms a circular hoop of radius 1m. It is fixed in a vertical plane. Two beads, A and B, of masses m and 2m respectively, are threaded onto the wire. The coefficient of restitution between the beads is 0.5. Bead B rests at the bottom of the hoop. Bead A is projected from the...

If a particle moves inside a loop then when is it's acceleration at a maximum? ie in a loop the loop

Homework Statement Homework Equations Centripetal Acceleration: a=v2/r or a=w2r where a= Centripetal Acceleration v= Linear Velocity r= Radius w=angular velocity The Attempt at a Solution Question Number 1: Drew a diagram of a circular with one point being O, another...

Hi :smile: A horizontal disc has a hole through its center. A string passes through the hole and connects a mass m on top of the disc to a bigger mass M that hangs below the disc. Initially, the smaller mass is rotating on the disc in a circle of radius r. What must the speed of m be such...

Hi, I was drawing the velocity vectors in circular motion to show that, the difference between them would yield an acceleration with direction towards the center of the circle. The problem I am having though is understanding from which point that accelerating takes place. I.e: A ball moves...

Not really sure where to start with this. I know it has something to do with conservation of energy but not really sure how to go about it.

Homework Statement http://img98.imageshack.us/img98/4571/kidswing.jpg Mass (m) of the kid sitting on the swing is 35 kg, and its center of gravity is at point C (the meeting place of the swing's arm EC with the arch p-r, created by the movement of the center of gravity of the kid). If the...

Can anyone help me solve this entire Physics question? It's on my exam, and I have worked out some of them, but I have no answers to compare to, so I was wondering if some of you guys can help QUESTION IS: A new Gravitron Ride is proposed for an amusement park in which the Gravitron will...

Homework Statement The first question reads: In riding a bicycle, it is noted that the 26 inch diameter wheel makes 15.0 revolutions in a time of 8.50sec. What is the angular speed of the wheel? What distance does the bicycle travel during this time? (in feet) (in rad/s) Homework...

Homework Statement The radius is 7ft, the diameter is 14ft, the person is 181lb and is 6ft 1in. How fast does he have to start the loop to be successful all the way around? How high does he have to start? Don't need to apply Friction. Homework Equations Cetripetal Force? Flo...

On pedaling a bicycle along a straight line, the friction act forward on the rear wheel and act backward on the front wheel. If I turn its handlebar so that the front wheel is at a certain angle (say theta) and pedal it in uniform circular motion, what would be the direction of the friction...

http://img864.imageshack.us/img864/9467/tnua.jpg I see an angle without a trigonometric function (delta theta - at the left side equations). I've never seen it before in a formula, and am not sure how to use it. Can anyone tell me how? Do I just translate degrees to radians and just plug the...

Homework Statement Find the time it takes for a particle initially at rest to travel around a circle with acceleration \ddot{\theta} = -3 \cos{\theta} to travel 1/4 of the circle.2. The attempt at a solution \int_{0}^{{\frac{\pi}{2}}}-3 \cos{\theta} Am I doing this right?

Homework Statement http://img685.imageshack.us/img685/9250/drawingmo.jpg In the drawing is depicted a pendulum hammer of an impact device (in both projections). The hammer is made out of shaft AB which upon it is held pendulum OM. At point M of the pendulum is a hammer. According to...

Homework Statement http://img200.imageshack.us/img200/2524/drawingsave.jpg Weight W that's 15 [N] does circular motion around shaft AB in a frequency of 300 turns per minute A) calculate the max tension force on shaft CD [there's another clause, but I rather just try A for now]The Attempt at...

Homework Statement A girl is running around a circular fountain with a diameter of 6.5m. If it takes her 72 seconds to run all the way around, what's her angular speed? The Attempt at a Solution I appear to be getting a wrong answer: (look only at the thick black marker)...

Homework Statement This is a very easy derivation (I think), I forgot how to do it though. How do you derive a = \frac{4\pi^2R}{T^2} or a = 4\pi^2Rf^2? Homework Equations The Attempt at a Solution They both mean the same thing since T is Inverse Frequency but I don't understand how...

Keys with a combined mass of 0.100 kg are attached to a 0.25m long string and swung in a circle in the vertical plane. a) What is the slowest speed that the keys can swing and still maintain a circular path? b) What is the tension in the string at the bottom of the circle?

A bus passenger has her laptop sitting on the flat seat beside her as the bus, traveling at 10.0 m/s, goes around a turn with a radius of 25.0 m. what minimum coefficient of static friction in necessary to keep the laptop from sliding?

Homework Statement A string attached to the center of a rod with radius R has a mass attached at the other end, moving with speed v0. Because of acceleration due to gravity the mass moves down while undergoing circular motion, causing the string to wrap around the rod. Find an expression for...

Hey there, The Question Points A,B,C,D, and E lie in a straight line. AB=BC=15 cm, CD=10 cm and DE=20 cm. A particle is moving with SHM so that A and E are the extreme positions of its motion. The period of the motion is 0.2s. Find the time the particle takes to get from B to D i) if it is...

Hi guys, :smile: Work Done = Force x Distance x cos of Theta - the angle between the Force and the Displacement Vector / direction of motion In Circular motion I know the force but I am given velocity. In order to prove that no work is done is it correct to say the following: If we have two...

So ya, the question that I'm trying to solve is to derive a=v^2/r using calculus. I am very intrigued when in class my teacher derive angular velocity \omega he did it very elegantly by starting off with the equation s=r\theta (s is the distance traveled) then ds/dt = d...