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.
Homework Statement
A string with the length of 4.23 m can support a weight of 25 g. If you add a weight and spin the string horizontally above your head, it breaks upon reaching a tangential velocity of 5.1 m/s. What is the mass of the weight?
so... radius=4.23m, V(t)=5.1 m/s, and...
This scenerio originated from
https://www.physicsforums.com/showthread.php?t=391796
where is was intended to argue that in the weak field limit where Newtonian gravity is a good approximation gravitational mass is gamma*m0=E/c2, as opposed to the rest mass argued for by several in that...
ell let's say there's a cabin and its rotating about its axisand we have a block of mass m
placed (not at the the centre of the cabin)
and there's some friction between the the block and the surface
now let's say the speed of the cabin is increased a lil high so that friction can no more...
Hi everyone!
I have a small question that bothers me. Consider a test particle in the Earths gravitational field on circullar obrit. Speciffic effective potential is
\begin{equation}
\widetilde{V}_{\rm eff(1)} = \frac{1}{2} \frac{l^2}{m^2} \frac{1}{r^2} - \frac{GM}{r},
\nonumber...
Homework Statement
Consider a bead of mass m that is free to move around a horizontal, circular ring of wire (the wire passes through a hole in the bead). You may neglect gravity in this problem (assume the experiment is being done in space, far away from anything else). The radius of the ring...
Homework Statement
Your favourite physics teacher who is late for class attempts to swing from the roof of a 24m long rope as shown in the picture. The teacher starts from rest (Ek=0) with the rope horizontal, but the rope will break if the tension force in it is twice the weight of the...
Homework Statement
A bucket is rotated in a vertical circle such that the water just does not fall. Radius of the circle is R. Gravitational acceleration: g. Find the Time period of one circular motion.
http://img148.imageshack.us/img148/6583/bucket.jpg
The Attempt at a Solution
I...
Homework Statement
This is for my mechanics class. It seems like it should be easier than I'm making it.
A single object of mass m is attached to the ends of two identical, very long springs of spring constant k. One spring is lined up on the x-axis; the other on the y-axis. Chpose your...
Homework Statement
A man sitting on the edge of his seat on a Ferris Wheel has a mass of 50.0 kg. The Ferris Wheel has a radius r=30m and the ferris wheel completes a single revolution every 20 seconds. Find the force between the man and the chair.Homework Equations
FNET=ma
Fg=mg...
Homework Statement
A space station has a radius of 200 meters. An astronaut has a mass of 55 kilograms and the station rotates at 1.5 rev/min. What is the period of rotation for the station?
Homework Equations
\tau=2\pir/v
a=v2/r
Fg=mg
FNET=ma
The Attempt at a Solution
I think...
Homework Statement
A pilot flies an airplane in a vertical circular loop at a constant speed of v = 160 m/s. If the pilot's apparent weight at the top of the loop is one-third of his true weight on the ground, find the radius R of the plane's circular path.
Answer: R= 1960m
Homework...
Hello guys, good morning. :)
I need your help regarding Circular Motion. I'm hoping that someone will help me heartily with this.
These are the following problems:
1. When the radius and mass are held constant, what do you expect to happen to the centripetal force if the frequency of...
Homework Statement
Basically, three different masses hanging on three strings of different lengths all different distances from the axis of rotation. They have a maximum tensile strength of 450 Newtons. I have to solve in variable form first, and however... Well, okay. Just check the image...
Homework Statement
The frequency of circular motion for a charged particle moving around in the presence of a uniform magnetic field does not depend on ...
a)The radius of the circle
b)The mass of the particle
c)The charge of the particle
d)The magnitude of the magnetic field...
Homework Statement
A curve of radius 65m is banked for a design speed of 105 km/h. If the coefficient of static friction is 0.34 (wet pavement), at what range of speeds can a car safely make the curve?
I am not sure how can I get range of velocities at which the car can travel without...
Homework Statement
A 4.80 g coin is placed 11.0 cm from the center of a turntable. The coin has static and kinetic coefficients of friction with the turntable surface of us = 0.770 and uk = 0.400.
What is the maximum angular velocity with which the turntable can spin without the coin...
This might be a really dumb question but I haft to ask it , if i have a bike wheel ,and on opposite sides I have 2 laser pointers shooting light straight up , the light is being shot up perpendicular to the rotation of the tire . If the wheel is going really fast can the light bend away from...
Homework Statement
A proton has an energy of 2.5 × 10−10 J. What force is needed to keep it going in
a circle having a 1.0 km radius
The Attempt at a Solution
so i tried to find v first.
total energy E = 2.5 x 10-10 J =\gamma mc2
so m = photon mass = 1.67 x 10-27
so i found...
Homework Statement
In a circular rotating room (think Gravitron), there are two blocks stacked against the wall and do not drop. Block A is touching block B, and block B is touching the wall.
Homework Equations
The Attempt at a Solution
I know how to do this problem, but I am not...
Homework Statement
Public skateboarding parks often include a well in the shape of a half cylinder (half-pipe). The skateboarder's path traces out a semicircular arc, with the midpoint of the arc at the lowest point. When starting from rest at one of the upper edges of the arc (at height h)...
Homework Statement
A 171 kg roller coaster car is on a track that forms a circular loop of radius 45.9 m in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its net inward acceleration at this point?
On the Round...
Hi guys,
I am very new to the forum (and physics itself). I have only started my O'levels but am a deep physics enthusiast for interesting problems.
When you have circular motion, and you take the displacement from a point on the circle, what type of:
Velocity-time graph...
Homework Statement
A concrete highway curve of radius 60.0 m is banked at a 11.0 degree angle. What is the maximum speed with which a 1500 kg rubber-tired car can take this curve without sliding? (Take the static coefficient of friction of rubber on concrete to be 1.0.)
Homework Equations...
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...
Guys, our thesis defense is near already. It will be this thursday. I just want to know some more real life applications of Circular Motion involving liquids. The experiment we performed was we placed water inside a bucket then we spin it around. (Vertically) Some water spilled but most of the...
Homework Statement
A rod of mass m and length L is suspended from one end, and swings as a pendulum (ignore friction from the hinge). It is released from rest when it forms an angle θ with respect to the vertical.
The moment of inertia of the rod about its rotation axis is mL2/3.
What is...
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
Homework Statement
A 4.03 kg object is attached to a 1.23 m long string and swung in a vertical circle at a constant speed of 18.5 m/s. What is the tension force on the string when the object is at the top of the loop?
Homework Equations
Fnet = (mV^2)/r
The Attempt at a Solution...
Homework Statement
An object of 6.0kg is whirled round in a vertical circle of radius 2.0m with a speed of 8.0m/s. If the string breaks when the tension in it exceeds 360N, calculate the maximum speed of rotation, and state where the object will be when the string breaks.
Homework Equations...
Homework Statement
Ignoring the motion of the Earth around the Sun and the motion of the Sun through space, find:
a) the angular velocity
b) the linear speed
c) the centripetal acceleration
of a body resting on the ground at the equator.
What would the length of a day be if the...
Homework Statement
A boy rides a Ferris wheel with a radius of 10.0m. The wheel completes one turn every 30.0s. Find the boy's acceleration at the lowest and highest points on the circular path.
Homework Equations
\frac{m(V_{max})^{2}}{r}=T-F_{w}
The Attempt at a Solution
I...
hi,
could some one explain where am i wrong?
A proposed space station includes living quarters in a circular ring 53.5 m in diameter. At what angular speed should the ring rotate so the occupants feel that they have the same weight as they do on Earth?
in such a station there is a centr...
Homework Statement
A particle of mass m is constrained to slide on the inside of a vertical smooth semi- circular ring of radius r. The position of the particle is described by a polar coordinate system whose origin is at the centre of the circle with axes along the orthogonal unit vectors...
For this problem, I tried using the equation:
ac=V2/r and put in
2000= ((2*pi*r)/(1/58))2*r
What is the distance of a sample of blood from the rotation axis of a centrifuge rotating at a frequency f = 3480 rpm, if it has an acceleration of 2000g?
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...
Hi again,
I'm sorry for all of the questions in this section. I am having the worst time trying to understand how to set up the problems. I know the equation for acceleration is a= V^2/r; however for this problem I am looking to find the velocity and time. Again, I would appreciate any kind...
Hi all,
I'm having a very difficult time with this problem. I know that the magnitude stays the same and it involves uniform circular motion, but I just can't seem to figure out how to begin the problem or what formula to use. I would really appreciate any kind of help.
A wall clock has a...
Ok, well my Honors Physics teacher doesn't really like to "teach" but rather give us a list of equations, and then throw a packet at us and tells us to do it. Last semester I got a C and I know that I could do much better if I was actually explained the information and how and when to apply the...
Homework Statement
A Jet pilot takes his aircraft in a vertical loop. if the jet is moving at a speed of 700km/hr at the bottom of the loop, determine the minimum radius of the loop if the acceleration at the lowest point doesn't exceed 6.0g's (this means 6.0 x acceleration due to gravity on...
Homework Statement
A ball on the end of a string is whirled around
in a horizontal circle of radius 0.28 m. The
plane of the circle is 1.44 m above the ground.
The string breaks and the ball lands 2.66 m
away from the point on the ground directly
beneath the ball’s location when the...
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...
I was absent from school for 3 days and my teacher gave this worksheet to me. I have no idea what I'm doing on it. Can anyone please help me with this? Thanks.
Homework Statement
A particle of charge Q is fixed at the origin of an xy coordinate system. At t = 0 a particle (m = 0.776 g, q = 5.04 µC is located on the x-axis at x = 18.7 cm, moving with a speed of 39.8 m/s in the positive y direction. For what value of Q (in μC) will the moving particle...