What is Uniform circular motion: Definition and 311 Discussions
In physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. It can be uniform, with constant angular rate of rotation and constant speed, or non-uniform with a changing rate of rotation. The rotation around a fixed axis of a three-dimensional body involves circular motion of its parts. The equations of motion describe the movement of the center of mass of a body. In circular motion, the distance between the body and a fixed point on the surface remains the same.
Examples of circular motion include: an artificial satellite orbiting the Earth at a constant height, a ceiling fan's blades rotating around a hub, a stone which is tied to a rope and is being swung in circles, a car turning through a curve in a race track, an electron moving perpendicular to a uniform magnetic field, and a gear turning inside a mechanism.
Since the object's velocity vector is constantly changing direction, the moving object is undergoing acceleration by a centripetal force in the direction of the center of rotation. Without this acceleration, the object would move in a straight line, according to Newton's laws of motion.
Hey Guys. I am having issues with one of my physics homework questions, and i was seeking help. The question is as follows:
While traveling around a roundabout, John notices that the fluffy dice suspended from his rear-vision mirror swing out. If John is traveling at 8m/s and the roundabout...
Can someone tell me how I am plugging this in wrong? And am I using the right equations? Thanks!
Homework Statement
A pilot is flying a vertical loop of radius 290 m, and at the top of the loop is pushing against the seat with a force of .25 "g's" {or Normal force = .25mg}. What is the...
Can someone look at this and tell me what I'm doing wrong? Thanks!
Homework Statement
You place a penny on a level rotating wheel at a point 5.00 cm from the center of rotation. You increase the speed of rotation gradually, and once you reach a rotational speed of 0.825 revolutions each...
Homework Statement
A pilot flies an airplane in a vertical circular loop with a radius of R = 1200 m. The plane is gaining speed as the pilot makes a dive, and its speed is measured to be 150 m/s when the plane reaches the bottom of the circle. If the total acceleration of the plane at the...
1. A 2kg bucket of water is attached to a 1.5m long string and swung in a vertical circle with a constant speed of 12 m/s. What is the minimum speed the bucket can be swung at while still retaining the water.
2. The bucket has a maximum tension force on the string at the bottom, with 212 N...
Homework Statement
As a pilot comes out of a dive in a circular arc she experiences an upward acceleration of 9.0 gs (i.e. 9 x 9.8).
a) Mentions that the Pilot's mass is 60 kg, already solved this
b) If the speed of the plane is 330 km/h, what is the radius of the plane's arc...
Homework Statement
David spins a sling in a horizontal circle above his head. What would happen to the period of rotation if he applied the same force and the length was a) doubled, b) halved
Homework Equations
ac = (4π2r) / T2
The Attempt at a Solution
Just not sure what to do in...
Homework Statement
A car with mass 1200kg rounds a curve banked at 18 degrees. The radius of the curve is 130 m.
Find the speed of the car if the frictional force between the tires and the road is 3.5 x 10^3 down the banked curve.
Homework Equations
ac = v2/r
The Attempt at a Solution...
So I've been pondering on this question for quite a while and I'm a little stumped. It's not a homework problem; just a problem I came across yahoo answers a week ago. Basically it's a true or false question:
Homework Statement
If a highway curve is properly banked and posted at 45 mph, it...
Homework Statement
A 2 kg car travels in a flat circle. At
a certain instant the velocity of the car is
24 m/s West and the total acceleration of the
car is 9 m/s
2
at 53 degrees
North of West.
What is its radius?
Answer in units of km.
Homework Equations
F=ma
w=(2pi)/T
a= w^2...
In a lab we were supposed to produce a rollercoaster ramp while it had a loop, and then to drop a marble at a height where it would finish the entire path without falling off, with enough centripetal acceleration at the loop. we were not given the mass of the marble, and we were only given a...
A new car is tested on a 200m diameter track. If the car speeds up at a steady 1.5 m/s^2, how long after starting is the magnitude of its centripetal acceleration equal to the tangental acceleration?
So we know that our acceleration is equal to 1.5 m/s^2, our radius of our circle is 100m. I...
Homework Statement
A proposed space station consists of a circular tube that will rotate about its center (like a tubular bicycle tire), as shown in the figure (http://session.masteringphysics.com/problemAsset/1057181/4/GIANCOLI.ch05.p048.jpg). The circle formed by the tube has a radius of...
1. Alright say you have a simple pendulum with given mass, length, and velocity (I think.. correct me if I'm wrong) ... how would I go about calculating theta (in degrees)?
2. I'm assuming the quadratic eq will have to be used? Among a couple of the simple force formulas.
3. I...
Homework Statement
you are sitting in an airplane. you have a window seat. the plane makes a level turn of 2km at speed 400km/hr. the coefficient of static friction btwn you and the seat is .35 Then they ask is the frictional force sufficient to keep you moving in a radius of 1km at a speed...
Homework Statement
A stone rests in a pail that is moved in a vertical circle of radius 60 cm. What is the least speed the stone must have as it rounds the top of the circle if it is to remain in contact with the pail?
Answer: 2.4 m/s
Homework Equations
v= 2 pi r / t
The Attempt at...
Homework Statement
A mass of 1.5 kg moves in a circle of radius 25 cm at 2 rev/s. Calcualte (a) the tangential velocity, (b) the acceleration, (c) the required centripetal force for the motion.
Answers:
A) 3.14 m/s
B) 39.4 m/s^2 radially inward
C) 59 N
Homework Equations
v=2piR/T...
Homework Statement
A cat sits on a merry go round at a radius of 4.0m from the center. The ride makes one complete rotation every 6.3 seconds. What is the least coefficient of static friction to keep the cat in place?
Homework Equations
Circumference = 2Pi*r
V=d/t
a=v^2/r
The...
Homework Statement
A particle's position is given by the formula
r(t) = Rcos(ωt)î + Rsin(ωt)ĵ
The particle's motion at t=0 can be described as a circle starting at time t=0 on the positive x axis.
a) When does the particle first cross the negative x axis?
b) Find the speed of the particle at...
Homework Statement
If a curve with a radius of 60 meters is properly banked for a car traveling 60 km/hr, what must the coefficient of friction be for a car on the same curve traveling 90 km/hr?
Homework Equations
Fmax = u * Fn
where Fmax = force causing the friction, u = coefficient of...
Homework Statement
Fuzzy dice hang from the rear-view mirror of a car rounding a curve. If the curve has a radius of 275 meters and the dice are hanging at an angle of 12° from the vertical, how fast is the car going?
Homework Equations
a = v2/R
for an acceleration with a constant...
Homework Statement
A purse at radius 1.90 m and a wallet at radius 2.60 m travel in uniform circular motion on the floor of a merry-go-round as the ride turns. They are on the same radial line. At one instant, the acceleration of the purse is (1.70 m/s2) + (4.60 m/s2). At that instant and in...
Homework Statement
Which, if any, of the following statements about a particle in uniform circular motion is/are true?
Its acceleration vector is a constant.
Its velocity and acceleration vectors are always perpendicular.
The direction of its acceleration is toward the center of...
Hello guys. I am taking an introductory course in computer programming. For one assignment I was to make up a word problem, then write a program to solve it. I wrote a program to calculate the radius of a circular orbit based on the orbiting object's current velocity, and other parameters. Can...
Homework Statement
Which of the following is not true in relation to an object moving in uniform circular motion?
a. KE of the object is constant
b. net force is zero
c. net work is zero
d. the magnitude of acceleration is constant
e. momentum is non-constant
The Attempt at a...
Homework Statement
In space in the absence of gravity, there is a post of "infinite mass," meaning that the post is fixed or "nailed down" and cannot move. A ball of mass m1 is connected to the post by a cable of negligible mass of length L1. A second ball of mass m2 is connected to the first...
Uniform Circular motion problem!
Homework Statement
A 235 m tall tower is built on the equator. Due to the rotation of the earth, how much faster does a point at the top of the tower move than a point at the bottom (in m/s)?
Homework Equations
v=w*r (w is omega)
The...
I see in the description of non-uniform circular motion in a textbook, referring to a ferris wheel, that the velocity of an object at the bottom must be twice the velocity at the top, but it is not mathematically shown and it is not immediately obvious to me. Can someone show a simple...
Sorry if this is the wrong (sub)forum!
I need some help to understand how to express the following:
The velocity vector
When this is given:
Omega
radius
Both in magnitudes. I want to obtain an expression for the velocity vector when the angle theta (radians/s) is changed. That...
1. we can derive that v=r\omega for uniform circular motion as v=2\pir/T and \omega=2\pi/T but does the relation v=r\omega also hold for non uniform circular motion where \omega is a variable quantity
1. The fast French train known as the TGV (Train à Grande Vitesse) has a scheduled average speed of 216 km/h. (a) If the train goes around a curve at that speed and the magnitude of the acceleration experienced by the passengers is to be limited to 0.050g, what is the smallest radius of...
Homework Statement
To find the velocity and acceleration vectors for uniform circular motion and to recognize that this acceleration is the centripetal acceleration.
Suppose that a particle's position is given by the following expression:
A.) Choose the answer that best completes the...
Homework Statement
The speed of the tip of the minute hand on a
town clock is 0.00182 m/s.
What is the speed of the tip of the second
hand of the same length?
Answer in units of m/s.
What is the centripetal acceleration of the tip
of the second hand?
Answer in units of m/s2...
Homework Statement
What angular speed (in revolutions per
minute) is needed for a centrifuge to produce
an acceleration of 675 times the gravitational
acceleration 9.8 m/s2 at a radius of 15.4 cm?
Answer in units of rev/min.
Homework Equations
ac=4 pi2 r f2
The Attempt at a...
Homework Statement
A point on the outer rim of a tire on a moving
vehicle exhibits uniform circular motion with
a frequency of 28 Hz. The diameter of the tire
is 40 cm.
How fast is the car moving?
Answer in units of km/hr.
Homework Equations
V=2 pi r f
The Attempt at a...
Hi, so I got stuck on this problem and I really don't know what it is that I'm not doing right, so if you can please help me. Thank you
Homework Statement
A satellite is in a circular orbit 11000 km
above the Earth’s surface; i.e., it moves on a
circular path under the influence of...
Hi people, i had my final exam yesterday, and one of the questions was this "a particle in uniform circular motion, moved for an interval of 0.185 seconds in a circular path of radius 16 cm, what is the angular velocity of the particle"?
I think that the question lacks information, am i right?We...
Homework Statement
Starting off a physics paper here about circular motion:
An Object is in Uniform Circular Motion. So Its acceleration is constant because acceleration is a vector quantity, its radial acceleration component is constant in magnitude and its tangential acceleration...
Homework Statement
A car, which weighs 1000 N, travels over a bumpy road with a constant speed. Gravity acts. The road at point B is in the shape of a circle with a radius of 100 meters...
Homework Statement
What is the period, T, of the satellite's orbit (G is the gravitational constant, 6.7 × 10-11 m3 kg-1 s-2) ?
(The picture is attached)http://online.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?courses/phys211/oldexams/exam1/sp08/fig18.gif
Homework Equations
a...
Homework Statement
A flat racetrack viewed from above has curves with radius of 50.0 meters and 100. meters. A car having a mass of 1.00 x 10^3 kilograms moves counterclockwise around the track at a constant speed of 20.0 meters per second. It takes the car 20.0 seconds to travel from C to D...
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...
1. Homework Statement
An 100g bead is free to slide along an 80cm long piece of string ABC. The ends of the string are attached to a vertical pole at A and C, which are 40cm apart. When the pole is rotated, AB becomes horizontal.
a) find the tension in the string
b) find the speed of the...
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
A motorcycle has a constant speed of 25.0 m/s as it passes over the top of a hill whose radius of curvature is 126 m. The mass of the motorcycle and driver is 342 kg. Find the magnitude of (a) the centripetal force and (b) the normal force that acts on the cycle.
Homework...
Homework Statement
A small remote-control car with a mass of 1.51 kg moves at a constant speed of v = 12.0 m/s in a vertical circle inside a hollow metal cylinder that has a radius of 5.00 m.
What is the magnitude of the normal force exerted on the car by the walls of the...
a Ferris wheel has a radius of 20.0m and it completes 1 revolution in 8.42 seconds
a) what is the speed of a point on the edge of the wheel?
The circle is divided into 8 triangles. I have determined from that that the arcs of the circle (8 of them) each equal 20m. Because the triangles...
Homework Statement
When powered up, a disk drive starts at rest and spins up with non-uniform acceleration. this lasts for 1.66 seconds after which it does not accelerate any more. how fast is it spinning at .87 seconds?
alpha(i)=605 rad/s^2
B=1.89
Radius=2.03 cmHomework Equations...