What is Circular motion: Definition and 1000 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.
Homework Statement
The task is to design a highway. I did a similar project last year but I have completely forgotten and have no clue what to do.
You have to design a banked, circular, clockwise highway exit. you knwo you have 5000 sq. meters. of land to build it on..you also know that the...
Homework Statement
Homework Equations
L = T-V
For constant frequency tangential velocity is (radius)*(w)
The Attempt at a Solution
I need to find r(t) using the Langrangian L = T-V
I just was not sure whether I am on the right track for calculating the total kinetic energy for the above...
Hi!
I was trying to understand circular motion and came across two problems. I would really appreciate if you could help me with those.
Question 1:
In the picture below let's assume that the angle θ is 1 radian, i.e. 57.3°, radius is 1 m. It would mean that the length of arc AB is also 1 m...
I' m trying to derive the work done by a torque from W = ∫ F ⋅ ds and I' ve looked up the internet, it said:
W = ∫ F ⋅ ds ( since ds = dθ × r ) ---------------------------------------- ( Line 1 )
it can be written as
W = ∫ F ⋅ dθ x r
this is a vector triple product , thus can also...
Homework Statement
If an object moves in a circular path with a speed that increases at a constant rate, which of the following can be concluded?
(A) The radial component of the force acting on the object is zero.
(B) The net force acting on the object is zero.
(C) The net force acting on...
Homework Statement
While learning to drive, you are in a 1 320-kg car moving at 34.0 m/s across a large, vacant, level parking lot. Suddenly you realize you are heading straight toward a brick sidewall of a large supermarket and are in danger of running into it. The pavement can exert a...
Homework Statement
Imagine a vertically placed clock. What forces have an effect on the object when it is in the position of 3am?
Homework Equations
No need od equations i guess.
The Attempt at a Solution
So I figured out that when the object is in the position of 12am then weight of the...
Homework Statement
You swing a 1.60m long string with a metal ball attached to its end in a vertical circle, such that the speed of the ball does not change but the rope is always taut. The tension in the string when the ball is at the bottom of the circle is 60.0N more than the tension when...
Homework Statement
A curious child finds a rope hanging vertically from the ceiling of a large storage hangar. The child grabs the rope and starts running in a circle. The length of the rope is 14.0m. When the child runs in a circle of radius 7.0m, the child is about to lose contact with the...
Homework Statement
An object moves at constant speed in a circular path. True statements about the motion include which of the following?
a) the velocity is constant
b) the acceleration is constant
c) the net force on the obj is 0 since its speed is constant
Homework Equations
hm none...
Homework Statement
Satellite 1 has mass m1 & radius R1 and satellite 2 has mass m2 and radius 2R1
Which satellite’s speed is greater?
Question and my attempt are shown in the attached file.
Homework Equations
V= √GM/R
The Attempt at a Solution
I am not sure if my steps are correct, but if...
Homework Statement :[/B]
One swings a rock at the end of a string. We wish for the string to remain taut and for the rock to travel in a circulat path, in a vertical plane. What mathematical condition must the centripetal acceleration of the rock satisfy for the string to remain taut when the...
Homework Statement
A 60 g ball is tied to the end of a 40-cm-long string and swung in a vertical circle. The center of the circle is 150 cm above the floor. The ball is swung at the minimum speed necessary to make it over the top without the string going slack.
If the string is released at the...
Homework Statement
A ball on the end of a string is whirled around in a horizontal circle of radius 0.250m. The plane of the circle is 1.06m above the ground. The string breaks and the ball lands 1.90m (horizontally) away from the point on the ground directly beneath the ball's location when...
A point mass in an uniform circular motion is continuously changing the velocity direction. To do it, it continuously need force (energy).
If we don't give any energy to the system it will anyhow continues its uniform circular motion. How it's possible, who gives the energy ?
(It's seems a...
Homework Statement
I can't understand why friction acts radially inwards when a body is rotating on a rough turntable. If the friction is removed, the body would move tangentially, hence it has slipping tendency tangential, not radially outwards, then shouldn't friction act tangentially...
Homework Statement
A 180lb pilot flies a verticle loop with radius 2000 ft at 350 mi/h. With what force does the seat fress upward against him at the bottom of the loop?
Problem 6.21
Homework Equations
##F=ma##
##F_c=\frac {mv^2} {r} ##
The Attempt at a Solution
There seems to be a...
I'm in the chapter of Uniform Circular Motion and I have a hard time understating centipetal acceleration. Until now I knew that acceleration describes "how fast velocity changes in magnitude" except projectile motion because when it reaches maximum height then g is going to change the direction...
Homework Statement
In circular motion what will be the change in velocity if initial velocity and final velocity is 2 m/s? From the left, in the 3rd diagram, if initial velocity and final velocity is 2 m/ s then what is the change in velocity? t = 5 s
Homework EquationsThe Attempt at a...
Homework Statement
A particle is moving parallel to x-axis in the positive direction with velocity v such that at all the instants the y -axis component of its position vector is constant and is equal to 'b'. Find angular velocity about origin.
Homework EquationsThe Attempt at a Solution
I...
All, I teach physics and would like do a hands-on lab where students are using motors to investigate the concepts of angular velocity and RPM. I've searched Amazon and eBay for low RPM toy motors, preferably those that could be easily powered with a couple of 1.5V batteries. Not much luck...
Homework Statement
See attached diagram and statement of problem
Homework Equations
Conservation of momentum ...
mv = MV + mv/2
mv/2 = MV
V = mv/(2M)
centripetal force...centripetal force equals weight at top of circle.
MV^2/L = Mg
V^2 = Lg
V = (Lg)^.5
The Attempt at a Solution
Set V = V...
Homework Statement
A light rod ##AB## of length ##2a## has a particle ##P## of mass ##m## attached to ##B##. The rod is rotating in a vertical plane about a fixed smooth horizontal axis through ##A##. Given that the greatest tension in the rod is ##\frac {9mg}{8}##, find, to the nearest degree...
What If the velocity of particle moving in a circular orbit has increased , would the particle be no longer in circular orbit or it would go in an orbit with bigger radius?
I've been given a question to find the magnetic flux density of the Earth if an electron is orbiting near to the surface. The answer to the question makes the magnetic force equal to the centripetal force and solves for B from there.
However, I am confused to why the gravitational force has no...
Homework Statement
A ##5 ~kg## mass performs circular motion at the end of a light, inextensible string of length ##3~m##. If the speed of the mass is ##2 ~ms^{-1} ## when the string is horizontal, what is its speed at the bottom of the circle?
(assume ##g=10~ms^{-1}##) (Ans: ##8~ms^{-1}##)...
Homework Statement
Why do the left wheels of a car rise when it takes a sharp left turn (that is it lurches towards the right)?
Homework Equations
$$a_c= V^2/R$$The Attempt at a Solution
I started by imagining the car as being a part of a very large ring, dx.
Since it's taking a left turn...
Homework Statement
In picture, i already solved this problem but i had a question about the bottom question..
So i solved for the acceleration and remember that i got a negative value, i then reasoned with the question and put positive value and was correct.. but then i started thinking about...
Homework Statement
There is a block of known mass m on a horizontal surface. The block is connected to a pulley via a rope. The other end of the rope is pulled vertically, downwards, with a known force F. The pulley has a known moment of inertia I and radius r.
Calculate the acceleration a of...
Homework Statement
This question is referring to the classic ball in a loop question where it is dropped from a height and slides into a loop de loop.
Derive an expression in terms of theta the velocity of the ball at the time it loses contact with the track. Theta is measured from the...
1. Homework Statement
In picture
Homework Equations
f=ma
v^2/r
The Attempt at a Solution
ΣFy=-mg - Fn = m(-v^2/r)
-55*9.8 - Fn = m(-v^2/r)
v= 16π/4.5 since circumference = 2πr divide by the rotations time taken per second = 11.17m/s
-Fn = 55(-15.6) + 55*9.8
Fn = -319
What am i doing wrong here??
I am writing a lab report on the effect of the radius of a string on the frequency of rotation on an object in horizontal uniform circular motion.
My hypothesis is:
If the radius of the string from the origin of rotation increases, then the frequency will decrease because frequency has an...
I understand that the centripetal force on an object of mass 'm' is (mv2)/r
However, isn't this for an object going around in a circle? Suppose I have a curve (0.0033x2+−1.0038x+98.2331). What would be the fastest speed around this curve on the bounds x ->
Please note that we would...
Homework Statement
A model yacht runs on a horizontal frictionless oval track as shown (viewed from above) in the figure. The curved parts of the track are semi-circles of radius ##R = 0.5 m##; the straight sides have length ##L = 1 m##. The mass of the yacht is ##m = 0.5 kg.##
A force of...
Homework Statement
The Russian Mir space station had a mass of 130 tonnes and orbited Earth at an altitude of 480km with an orbital speed of 7621.4m/s. The diameter of Earth is 12 760 km.
a) What centripetal force was acting on it?
b) Find the value of the acceleration due to...
<< Mentor Note -- Two threads on the same subject have been merged >>
I am a junior enrolled in IB Physics at the standard level at my high school. As a part of the curriculum we must perform an Internal Assessment (IA) which involves performing an experiment and performing calculations and it...
Homework Statement
What is the distance from the Earth's center to a point outside the Earth where the gravitational acceleration duo to Earth is 1/10 of its value at the Earth's surface?
Homework Equations
F = Gm1m2/r2
F = m1 (v2/r)
Mass of Earth = 5.98x1024
G = 6.67x10-11
The Attempt at a...
In circular motions, one can measure the NetForce on an object with this formula:
ΣF = m*v^2/r.
But is this formula valid even if the orbital speed of the object is constantly increasing (or constantly decreasing)?
I and my teacher argued whether a uniform circular motion in polar coordinates is considered to be a motion in one dimension or it's a motion in two dimensions.
I am having trouble understanding tangential speed as it applies to uniform circular motion and I would appreciate any help.
Say I have a ball on the end of a string that I hold with my hand and rotate at a constant speed. If the string provides the centripetal force and acceleration, where...
Homework Statement
We have an object rotating inside a circular container. The rotation is vertical (see picture below).
The radius r of the container is given. Find the frequency (which then ties back to finding the centripetal acceleration) necessary, so that the objects rotating inside the...
Homework Statement
Keys with a combined mass of 0.100 kg are attached to a 0.25 m long string and swung in a circle in the verical 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...
Homework Statement
An object of mass m = 1 kg moves along a circular frictionless path of radius R = 0.5 m from point A to point B at which it makes an angle θ with the vertical direction as shown in the figure. If the object is release from rest (VA = 0) and θ = 30° , what is the normal force...
Homework Statement
l=2m
b=1.5m
The mass of the chair is 5kg.
A boy with a mass of 50kg sits on the chair.
The distance of the chair from the pole is 3m, and it spins around it horizontally with a radial velocity of 1.95 rad/s.
The boy drops a ball at some moment, what would be its distance...
A mass m = 0.15 kg is attached to a massless string and rotates at constant speed v = 4 m/s in a horizontal circle of radius 2 m. The tension T (in N) in the string is: (a) 1.1 (b) 1.9 (c) 2.4 (d) 3.3 (e) 4.9
I would assume that first I calculate the centripetal acceleration by using v^2/r =...
Homework Statement
An object of mass m is rotating, hanging from a string of known length l. The string is attached to a pole, which rotates with a known angular velocity ω and forms a to-be-determined angle α with the string. Find α.
I think I have solved it (the numbers match the results of...
Homework Statement
Gravity causes a centripetal force that allows satellites to travel around planets.
How fast must a 102-kg satellite travel to maintain a circular orbit 352 km above Earth's surface?
Homework Equations
F=m(v^2/r) -----> (F/m) x r= v^2, then square root
F= force
m=mass...