A circular economy (also referred to as "circularity") is an economic system aimed at eliminating waste and the continual use of resources. Circular systems employ reuse, sharing, repair, refurbishment, remanufacturing and recycling to create a closed-loop system, minimising the use of resource inputs and the creation of waste, pollution and carbon emissions. The circular economy aims to keep products, equipment and infrastructure in use for longer, thus improving the productivity of these resources. Waste materials and energy should become input for other processes through waste valorization: either as a component or recovered resource for another industrial process or as regenerative resources for nature (e.g., compost). This regenerative approach is in contrast to the traditional linear economy, which has a "take, make, dispose" model of production.In recent years, concepts based on (re-)cycling resources are increasingly gaining importance. The most prominent among these concepts might be the circular economy, with its comprehensive support by China and the European Union. There is also a broad range of similar concepts or schools of thought, including cradle-to-cradle laws of ecology, looped and performance economy, regenerative design, industrial ecology, biomimicry, and the blue economy. These concepts seem intuitively to be more sustainable than the current linear economic system. The reduction of resource inputs into and waste and emission leakage out of the system reduces resource depletion and environmental pollution. However, these simple assumptions are not sufficient to deal with the involved systemic complexity and disregards potential trade-offs. For example, the social dimension of sustainability seems to be only marginally addressed in many publications on the Circular Economy, and some cases require different or additional strategies, such as purchasing new, more energy-efficient equipment.
Homework Statement
Evaluate \int_C \vec{F} \cdot d\vec{r}
Where \vec{F} is the field generated from a circular thread of radius b in the xy plane, with magnitude j in the direction \hat{\varphi} (i.e. not along the curve, I take it)
C: (x,y,z) = b(1+ \cos{\alpha}, 0, \sin{\alpha})
3. The...
Homework Statement
The potential energy of a particle of mass m is V(r) = k/r + c/3r^3 where k<0 and c is a small constant. Find the angular velocity \omega in a circular orbit of radius a and the angular frequency \omega' of small radial oscillations about this circular orbit. Hence show...
Hi,
I wish to manufacture a transition tube from 4"x1" rectangular section to 3" OD circular section. The height of the part is 3" and is supposed be around 2 mm (.082") thick. Currently I am planning to manufacture this in a hydraulic press using (custom made ) end forming tools. The forming...
1. A uniform right circular solid cone of weight W is suspended by two vertical strings attached to the ends A and B of a diameter of its base. If the cone hangs in equilibrium with its vertex vertically below A, find the tension in the strings.
2. Centre of mass of cone from the vertex is 3/4...
I'm unsure about the sign of the circular polarization.
Assume the magnetic field is pointed toward the observer.
In the Zeeman effect spectrum, is the CCW polarized emission at higher or lower wavelength than the CW polarized emission.
I think the CCW polarized emission is higher, and this is...
Homework Statement
Given-
Mass of particle=m
Radius of the circular path=r
Magnitude of linear momentum= p
Find the radial force acting on the particle.
Homework Equations
p=mv
acentripetal=v2/r
The Attempt at a Solution
Fradial=macentripetal
=mv2/r
=mv2×m/r×m...
Homework Statement
A ball was placed in a frictionless circular track with radius R and given initial velocity of u.The ball went around the cricle ,left at some point,then arrived in the same initial position after undergoing projectile motion.
a.State the speed u in terms of R and g...
A particle travels along a circular arc segment centered at the origin of the Cartesian plane with radius R, a start angle θ1 and an end angle θ2 (with θ2 ≥ θ1 and Δθ = θ2 - θ2 ≤ 2π). The total distance traveled is equal to the arc length of the segment: L = R(Δθ).
I would like to find the...
Homework Statement
A circular single loop of wire with a diameter of 20.0 cm lies in the plane of the paper in a region of space that contains a 1.75 T magnetic field pointing out of the paper.
a) Determine the magnetic flux through this loop.
b) If the diameter of the loop changes from 20.0...
Homework Statement
https://session.masteringphysics.com/problemAsset/1383558/3/21.EX26.jpg
Make a table with rows labeled P, Q, and R and columns labeled r1, r2, Δr, and C/D. Fill in the table for points P, Q, and R, giving the distances as multiples of λ and indicating, with a C or a D...
Hello there!
I'm currently doing some mathematical modelling at my work, and I have arrived at an interesting kind of circular relationship integral - and now I'm wondering about what to do.
The integral looks very innocent at first glance:
$$ \theta_s = \int\limits_0^{t_1} \omega (t) dt$$
So...
If a force acts on an object perpendicular to its velocity, why does the speed remains unchanged? Wouldn't the force give rise to a vertical component of velocity on the object and thus increase the speed of the object?
Why do we take the Center of mass to be on the right side rather than on the left?
A uniform circular disc of radius 4a with a circular hole of radius 2a made in the disc.
The mass of L is m and a particle of mass km is now fixed to L at the point P. The system is now suspended from the point S...
In the elementary proof of the slant surface area of a cone ##A=\pi r s##, where ##s## is the slant height, it is assumed that the net of a cone is a circular sector. In other words, if we cut the slant surface of a cone from its apex to its base along a straight line, the resulting surface can...
Homework Statement
Calculate the gravitational force between a point mass and a circular platform.
Homework Equations
G=m1*m2/r^2
The Attempt at a Solution
http://i.imgur.com/dfZf9GK.jpg
The actual solution is different. They integrated by the angle between a/r (alpha) but i do not...
Hey, I'm having some difficulty in understanding circular motion and it's forces. Here is the situation I'm on:
Imagine you are on a smooth turn-table with smooth shoes and the table starts spinning. Because of inertia, and because the frictional force is not nearly enough to keep you going in a...
Now,we get the circular polarization photon using 1/4 waveplate, can we make a circular polarization laser directly through Stimulated Emission Radiation?
or, when a electron transition from one level to another level,what kind of polarization of the photon, linear or circular?
thank you!
< Mentor Note -- thread moved from New Member Introduction Forum >
Hello, this is actually my first post on Physics Forums (I just joined)
The question above is the one that I thought that would grab the most attention.
I actually have 3 questions concerning magnets...
I require a special...
For the case of a particle attached to an inextensible string which is hanging at rest and then provided an impulse horizontally, what conditions must the system meet in order to allow for COMPLETE circular motion. I am well aware the tension at the apex of the motion must be satisfy one of the...
If I have a some a wire and I took part of it and created a circle. If I want to calculate the strength of the magnetic field at the center of it. I should just use the magnetic field equation for the circular loop, shouldn't I?
## B = \frac{U_o N I}{2R} ##
and I shouldn't care about the...
Homework Statement
The rod OA rotates clockwise with a constant angular velocity of 6 rad/s. Two pin-connected slider blocks located at B move freely on OA and the curved rod whose shape is a limacon described by the equation r = 200*(2-cosθ) mm. Determine the magnitude of the acceleration of...
Homework Statement
A car has an initial speed v0= 20m/s. It increases its speed along the circular track at s=0, at=(0.9s) m/(s2), where s is in meters. Determine the time needed for the car to travel 35m. The radius of curvature of the track is 40m.
Homework Equations
an = v^2/p
a = dv/dtThe...
Let's say I have a stone tied to a string and I'm spinning it vertically. Now, if I provide an initial velocity such that the velocity of the stone = 0 at an angle greater than 0 from the horizontal(visualize it in the "first quadrant") the eq of motion would be: T+mgsin (theta) = mv^2/r. If the...
Hi everyone!
I have the following problem. I have a two phase flow in a circular pipe and I want to model it. I need to decide and justify whether the model should be 2D or 3D. For the moment, I can say only one thing: considering z-axis in the length direction (that it is the dominant one) I...
Homework Statement
[/B]
find the period with only using L (for the long of the rope), R (for the radius), M (for the mass), and G (for the gravity)
Homework Equations
V=ωR
Fcentripetal = ##\frac {MV^2} {R}##
Fgravity = MG
phytagoras
basic trigonometry
The Attempt at a Solution
[/B]
i have...
Homework Statement
Homework Equations
ΣF=0
The Attempt at a Solution
Basically I don't agree with this solution, I think it is R1 + R2 - mgcos5 + mv^2sin5/r = 0. Can you help me please?
thanks!
What is the equation of forces please for the axis parallel to the banked road? Is it R1+R2-mgcosθ=mV^2/r or R1+R2-mgcosθ=-mV^2/r? Can you advise me please?
Homework Statement
An object moves in uniform circular motion. Its kinetic energy is directly proportional to:
I. centripetal force
II. radius of the circle
III. the period of circular motion
Homework Equations
I took the universal gravitational law
G* m1 * m2 /r^2 = m2 * v^2/r
and then I...
When deriving the magnetic field strength due to a circular loop at some distance away from it's center (using Biot-Savart's law), why is the angle between ds and r 90 degrees?
This is a youtube video with the derivation, see 5:55
Having trouble with the following problem:
A small particle slides along the bottom of a 10 inch radius circular bowl. Neglect friction and assume small oscillations. If the particle has a speed of 15 in/s when it is at the bottom of the bowl, determine
a. The differential equation governing...
Hi I am trying to understand what forces are at work to slow a liquid flowing in a circular pipe
As an example the above torus pipe fully filled with an incompressible low viscosity liquid. This is rotated until the fluid achieves solid body rotation and then the pipe is suddenly stopped...
Homework Statement
I have two questions. I'm not sure if I'm allowed to post two at once so I'll start with one
"Twenty boys and twenty girls are to take a ride on a Ferris wheel with twenty pods. How many ways can they be arranged if each pod is to contain one boy and boy girl"
Homework...
Homework Statement
Find the volume of a right circular cone with height h and base radius r.
Homework EquationsThe Attempt at a Solution
I've chosen the case where y = x = r = h. Then, I solve the integral in the image above and I got the book's answer. But is it actually correct?
As I understand it, satellites orbiting the Darth are constantly falling but keep missing. Why then is their speed constant? Why do they not tangentially accelerate like spaceships do when using a gravity assist?
I understand that the force of gravity is perpendicular to the satellites motion...
Homework Statement
Homework Equations
I know that Fc = m * centripetal acceleration, where the Fc = the force of gravity
The Attempt at a Solution
[/B]
I was able to use process of elimination to get B for 25 correctly, but I am not able to understand how it is the right answer.
How can...
Say we have an observer in perfectly circular motion around a source, like a star.
Is it reasonable to apply the angle change formula ##cos \theta_o = \frac{cos \theta_s - \frac{v}{c}}{1-\frac{v}{c}cos \theta_s}## and then take the component of the motion parallel to the light wave in the...
Homework Statement
A marble rolls from the top of a big sphere. What is the angle θ when the marble is about to leave the sphere? Assume a zero speed at the top.
Homework Equations
The question came from the chapter Mechanics - circular motion.
The Attempt at a Solution
I can't conceive what...
Hi, so, I got help from this homework problem by posting it on chegg, but I want clarification.
A circular loop of wire of radius 12.0 cm is placed in a magnetic field directed perpendicular to the plane of the loop and into the page. The field is decreasing at a constant rate of 0.050 T per...
Homework Statement
A satellite with mass 848 kg is in a circular orbit with an orbital speed of 9640 m/s around the earth. What is the new orbital speed after friction from the earth’s upper atmosphere has done -7.50·109 J of work on the satellite? Does the speed increase or decrease?
Homework...
Homework Statement
A 0.5 kg ball is swung in a circular path from a 80 cm long rope, attached to a vertical pole.
A. What is the speed of the ball theta (between the pole and rope) is 40 deg?
B. What is the KE of the ball at theta = 40 deg?
C. The ball slows down and the KE drops to 50% of the...
Homework Statement
In the simple mass spectrometer shown in the figure below, positive ions are generated in the ion source. They are released, traveling at very low speed, into the region between two accelerating plates between which there is a potential difference ΔV. In the shaded region...
Since the latex is not appearing, I request you to please click https://brilliant.org/discussions/thread/time-period-of-vertical-circular-motion/ , to view with complete formatting.
Please help.
Thanks.
P.S-This is not schoolwork or homework...
Homework Statement
You tie a cord to a pail of water, and you swing the pail in a vertical circle of radius 0.700 m
What minimum speed must you give the pail at the highest point of the circle if no water is to spill from it?
Homework EquationsThe Attempt at a Solution
I got the correct answer...
Hi, thanks for taking a look!
A toy train rolls around a horizontal 1.4-m-diameter track. The coefficient of rolling friction is 0.12.
(a) What is the magnitude of the train's angular acceleration after it is released?
(b) How long does it take the train to stop if it's released with an...
Hi
In one of my application I am using a linear actuator to lift a 30kg lid which has a diameter of 380mm.
I can only use 1/3rd portion on the lid to take support, for actuator which I used a 60*20*180 long plate mounted to the lid and lift.
How to calculate the deflection of lid when lifted to...
Homework Statement
The County Fair Swing carries the mass of riders and chairs in a circular path in a horizontal plane while suspended by cables or chains. Let's assume that:
Each chair with riders is supported by a single cable
The tension in the cable equals 2 x the total weight riders...
Homework Statement
A roller coaster at the Six Flags Great America amusement park in Gurnee, Illinois, incorporates some clever design technology and some basic physics. Each vertical loop, instead of being circular, is shaped like a teardrop. The cars ride on the inside of the loop at the top...
Homework Statement
EM wave with circular polarization travels in directon z interferes with perfect conducting surface xy.
1. find reflected wave
2. calculate induced charge density and surface current induced on conducting surface
Can you verify if I started point 1. correctly, and give...