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.
Hi guys! I have a rather brief question regarding circular free fall orbits in the Schwarzschild geometry. Consider an observer in a circular orbit in the equatorial plane at some allowed ##r = R##. The angular velocity as measured by an observer at infinity is given by ##\omega^2 =...
Homework Statement
A satellite is orbiting 600km above the Earths surface. The free fall speed is 8.21 m/s^2. The radius of Earth is 6400km.
What is the satellites speed, and the time interval for one orbit around Earth.
Homework Equations
v = ((2)(PI)(r))/T
ac = rw^2
w = (2)(PI)...
Homework Statement
How would I go about solving this Newtonian problem?
A truck is going around a circular track of radius 72m, banked at 60degrees. A spider rests on the inside wall of the truck. The coefficient of static friction b/w truck wall and spider is .91. Find the max speed that the...
Homework Statement You swing a marble with mass m attached to the end of a string in a horizontal circle as shown in the figure below. The angle that the string makes with the vertical is
θ = 37°.
(a) Find the speed of the marble when the string is 26.0 cm long.Homework Equations
soh,cah,toa...
Homework Statement
The Attempt at a Solution
So I just want to ask any of you who know physics pretty well if I am on the right track on this question, so it is asking for the magnitude of the acceleration of the car, and the direction. The magnitude of acceleration is (v^2/R) v = velocity and...
Uniform Circular Motion "A Jet Pilot"
Hi, my apologies if this has been posted before. I was just wondering if someone could help look over this question for me and confirm if I did it correct or not. It is a written homework rather than online so I can't check my answer to see if I did it...
Homework Statement
A small object of mass m1 moves in a circular path of radius r on a frictionless horizontal tabletop. It is attached to a string that passes through a frictionless hole in the center of the table. A second object with a mass of m2 is attached to the other end of the...
Homework Statement
Homework Equations
General solution:
Fourier series:
where r_{1}=a, r_{2}=b, f_{1}(\theta)=sin(\theta), and f_{2}(\theta)=2sin(\theta)cos(\theta).
The Attempt at a Solution
By evaluating the Fourier series shown above, I determined that...
Hi guys,
Can you help me I am stuck:
By finding the real and imaginary parts of z prove that,
$$|\sinh(y)|\le|\sin(z)|\le|\cosh(y)|$$
i have tried the following:
Let $$z=x+iy$$,
then $$\sin(z)=sin(x+iy)=\sin(x)\cosh(y)+i\sinh(y)\cos(x)$$
$$|\sin(z)|=\sqrt{(\sin(x)\cosh(y))^2+(\sinh(y)...
Dear all
I am having a problem on circular flow of fluid. On all books I have read they say
\frac{dp}{dr}=\rhov^{2}/r
Which make sense by using infinitesimal square volume and take the force exert.
But if I use a circular infinitesimal volume (which is usually the case for circular...
Homework Statement
Find the electric field a distance above the center of a flat circular disk of radius R, which carries a uniform surface charge σ.
Homework Equations
The Attempt at a Solution
Basically, I want to solve this usually trivial problem without using symmetry arguments and the...
Homework Statement
"A 40 kg child sitting 6.0 m from the center of a merry-go-round has a constant speed of 6.0 m/s. The net work (in Joules) done on the child after making one complete circle on the merry-go-round is?"Homework Equations
a=V^2/r
F=ma
C=2pi*r
The Attempt at a Solution
C ≈...
Homework Statement
Hi!
I have a problem with an assignment and need som help. The question is:
You’ve just completed an analysis of where the Space Shuttle must be when it performs a
critical maneuver. You know the shuttle is in a circular prograde orbit and has a position
vector of:
ro=...
Homework Statement
http://gyazo.com/fa8026ffdf2ccb97d0b09b9e74460455
Homework Equations
Fnet=mg
The Attempt at a Solution
I said that the letter B was the normal force which I derived from just drawing an FBD of the ball on the left side of the code
For acceleration I used...
Homework Statement A carousel takes 1.5 min to complete one revolution while rotating at a constant rate. A person rides on the carousel platform at a distance 3.2m from the center.
(a) From its state of constant rotation, the carousel then uniformly slows to a stop in time (delta t). Produce...
Homework Statement
Hi
I am looking at a circle in a Cartesian coordinate system (x, y, z), with center at the point (0, 0, L) and radius R (so the z-axis is normal to the surface of the circle). From the origin (0, 0, 0), I would like to integrate across the circular surface, i.e...
Homework Statement
An object travels counterclockwise on a circular path with radius R and constant angular
acceleration α, so that
vector r(t) = R cos(αt^2/2) i^+ R sin(αt^2/2) j^
Homework Equations
b. Find the time T when the object made a single revolution and returned to...
Units for Speed Pertaining to Circular Motion
Hi,
So v=ω*r
Where v = velocity in m/s
ω = angular velocity in rad/s
r = radius in m
But I am confused...the units don't match! What happens to the rad?
m/s = (rad/s)*s
My textbook doesn't explain it, it simply does calculations...
Homework Statement
A car enters the circular road with radius r = 200m at a
speed of v = 80km/h. A radar gun at O needs to rotate with constant angular
acceleration d^2θ/dt^2 = 0.025 rad/s2 to follow the motion of the car along the circular road.
a) Determine the acceleration of the car...
Just started this Analytical Mechanics class, so I figured this question should go here...
I've been pretty stuck with a problem. I felt like I totally knew what I was doing but I've become very stumped.
We're given the vector for general circular motion...
I have some questions referring to wave plates.
We have an entangled pair of photons as |H>|V> - |V>|H> and both go through 22.5 degree orientated half-wave plates. |H> is converted to |45> and |V> is converted to |135> (so the description is now |45>|135> - |135>|45>). So inputting the...
why are we considering speed is constant to find velocity a particle in uniform circular motion, is it possible for a particle in a circular motion to have constant velocity?
Hey guys, I was wondering if anyone could help me out with this problem from the GRE practice exam:
I honestly don't know how to go about solving it. I'm guessing that the answer is either B or D, however I know that in this GRE exam you can never guess... My friends think the answer is...
Hello! I have a few doubts in circular motion and I'd really appreciate your help :)
1) There is a statement in my book ( I have attached images - the first one) according to which the only horizontal force towards the center on the vehicle is friction. I know that some centripetal force is...
This is a problem I encountered while studying/practicing for my upcoming MCAT exam:
Homework Statement
A 1kg block slides down a ramp and then around a circular loop of radius 10m. Assume that all surfaces are frictionless.
1)What is the minimum height of the ramp required so that...
If i took my pencil to a place in space without gravity or air resistance and i spun it, would it spin forever? I mean its undergoing a centripetal acceleration, so energy has to come from somewhere to keep it spinning right? (and of course this is not meant to be an idea for perpetual motion, i...
Homework Statement
Consider AdS_5 space in Poincaré coordinates with metric ds^2=\frac{dz^2+dx_\mu dx^\mu}{z^2}. There is a circular Wilson Loop with Radius R in the Minkowskian boundary of AdS_5. We want to find the surface of minimal area in AdS_5 that has this loop as boundary.
We choose...
Science isn't the kind of "circular dynamic" I thought it was.
"Why the laws are as they are is a pretty easy question to answer."
The statement above really bothers me.
Why is C constant? Why does mass distort space-time? ...
Experiment tells us what the laws are
but experiments don't...
I was thinking of this problem recently and thought it'd be best if I got an answer from a physicist (or anyone else who'd know how to solve this).
Imagine a thin rubber pipe about a meter long. Holding each end of the pipe with both hands (respectively), you bend the ends inwards to form a...
Homework Statement
I am trying to understand game of roulette through kinematic equations of circular motion. Roulette is game where a ball spins in circular motion. Initially it is accelerated such that velocity of ball increases with time however after reaching its peak value it starts to...
Homework Statement
A plane is traveling at 200 m/s following the arc of a vertical circle of radius R. At the top of its path, the passengers experience "weightlessness" .To one significant, what is the value of R ?
Homework Equations
Mv^2/R=Mat , N=mg(1+at/g)
Velocity orbit =...
How does circular DNA wrap around a histone to form a chromosome? Or does it?
I am having a hard time visualizing this for any sort of circular DNA: prokaryotes, mitochondria, etc.
(This question was inspired by my reading about biology and reading that circular DNA does, in fact, form...
Homework Statement
A car of mass m takes off from rest around a circular track of radius r . Speeding up at a constant rate, the car takes t seconds to go around the track once. What is the magnitude of the net force acting on the car at the end of the trip?
Homework Equations
a_rad...
Hello,
Regarding acceleration in circular motion, my textbook says the total acceleration
of an object traveling in a circular path, can be computed by:
a = \sqrt{a^2_c + a^2_t}
and can be proved by pythag. thm.
Can someone help me understand this intuitively?
Thanks.
Homework Statement
Hi, I am having problems trying to solve an electrostatics question. Basically there are two circular sectors of radius R and with angle 2β. Both of these sectors have their vertices at the same point in the xy plane (ie at the origin) but have a separation d in the z...
Sorry about the intriguing title; this is just a continuation of the discussion in https://driven2services.com/staging/mh/index.php?threads/5216/ from the Discrete Math forum. The original question there was how to introduce mathematical induction in a clear and convincing way. Since the current...
Why is there only a radial component of acceleration present if a body is undergoing uniform circular motion whereas in non uniform circular motion both tangential and radial component of acceleration are present?
It is like the throws in hammer throw, when an object is swung circularly, the it does contains an rotational energy right? when it is release, how the energy affect the objects? Does the energy change to velocity tangent to the circular path it swung?
Prove the following
If f has a simple pole at z=c and C_r is any circular arc bounded by \theta_1 , \theta_2 and centered at c with radius r
\lim_{r \to 0^+} \int_{C_r} f(z) \, dz = i ( \theta_2 - \theta_1 ) \text{Res} (f;c)
If an object is orbiting on a circular time-like geodesic path around a mass then the Wikipedia claims that the first component of its four-velocity is given by
\frac{dt}{d\tau} = \frac{1}{\sqrt{1-\frac{3}{2}\cdot \frac{r_0}{r}}}
where r_0 is the Schwarzschild radius.
Is this right and how...
This began as homework that our Physics teacher set us. However, for some reason he decided no to collect it. I am curious as to whether or not this display my understanding of the topic well as communication is main area my teacher believes I need improvement in.
Homework Statement
Write a...
In uniform circular motion only a radial component of acceleration is present i.e centripetal acceleration. So why doesn't the particle following uniform circular motion go radially inwards due to radial acceleration?
Problem:
Consider two particles a and b moving in opposite directions around a circle with angular speed ## \omega ##. At ## t = 0 ## they are both at the point ## \vec{r}=\ell \hat{j} ##. Find the velocity of a relative to b if the radius of the circular path traced out by the...
physics circular motion and gravity help please :(
Homework Statement
1. a) A solid homogeneous sphere of mass M = 4.80 kg is released from rest at the top of an incline of height H=1.35 m and rolls without slipping to the bottom. The ramp is at an angle of θ = 25.7o to the horizontal...
Homework Statement
1. The mass of a star is 1.830×1031 kg and it performs one rotation in 37.30 days. Find its new period (in days) if the diameter suddenly shrinks to 0.850 times its present size. Assume a uniform mass distribution before and after.
2. A pulley with mass Mp and a radius...