Besslers prime mover and its enabler.

[Fletcher]

3 chaps go out for a game of curling, dax, RH, and FT .. the curls are magical curls, they don't have any friction losses whether stationary or in motion - dax, RH, and FT are competitive and like a little gambling - so they put a little wager on it, who will buy lunch - but - there is a problem - they are magical curls - so trying to get the closest to the bullseye will be a nonsense as they will all sale on by - so they decide the bet is on who can cross the finish line the closest to 5 meters per second ..

They toss a coin for who will start etc .. RH sets himself and gives the curl a big but short duration push - not bad .. Ft gets down into position and gives his curl a small but long and slow push - also not bad .. dax is itching to go - he assumes the position and gives it a small shove and waves at his mates - but it is going way to slow so he runs up behind it and gives it another wee shove - still too slow, so he does it again ..

The photo finishes showed all 3 curls crossed the line at the same speed of 5 m/s - when the force x distance was added up for each of them it was exactly the same total .. dax brought lunch for the hungry buggers coz he had crossed the start line a number of times ..

[Fletcher]

dax .. when an object is rolling it has translation KE and Rotational KE adding to a total KE .. but depending on their MOI's the proportion of each will be different, assuming they were released down the same track etc ..

A force can do the most work when it is in line with whatever it will eventually roll into and impact - that's the translational (linear) energy which is highest for the sphere, then disk, then ring ..however they all have rotational KE in varying amounts and the order is this - rings, disks, spheres - this force/energy is not in line with the object it will impact - it's at right angles to it so this portion of the total energy can not do any work on the object it impacts .. energy is capacity to do work , and is also f x d ..

[eccentrically1]

Ecc1: "The discs and hoops example involves inertia distributed about an axis in different forms.
Sure , one form takes longer to start. Because it has a different moment of inertia; a different resistance to acceleration even though it’s the same mass. Oranges."

Inertia apply to everything. No matter what mass you start from rest. If you repeatedly restart it takes more energy. It is not apples to oranges. It is apples to apples.

To compare the discs and hoops to the car, you might ask Chat what happens if the discs and hoops slip down the incline without rolling.
No examples have ever shown to violate thermodynamics. Chat is quite sure of that.

[Robinhood46]

I like the bit about Dax buying lunch.
I think I'm getting lost with the rest of it.
I can't see why we are bringing magical curls, or imaginary environments, into a question about energy and it's relation to friction, because It is how friction is overcome in the different scenarios, that affects the energy needed in each case.
I still think Fletcher should be buying lunch.

[Fletcher]

Outta luck RH - I don't do breakfast or lunch lol ..

Right at the beginning it was stated that objects in contact have static frictions when stopped, and rolling frictions when rolling, and air drag frictions when rolling - if you give the car a push and let it glide to a stop, and then give it another push etc - it has a different mix of frictions impeding its motion and you have to push a little harder each restart to overcome static friction ..

[Robinhood46]

The difference with the hoops and the discs is the rotational acceleration of the mass, the hoop needs all of it's mass to accelerate to rotate faster and the disc only needs a fraction of it's mass to accelerate faster (proportionately).
If they slide there is no rotational acceleration.

[Robinhood46]

Outta luck RH - I don't do breakfast or lunch lol ..

That doesn't matter, when you have your evening meal, it will be perfect timing for my breakfast.

[Fletcher]

All this talk is making me hungry and it's lunch time - wonder what's in the fridge ;7)

[daxwc]

Ahhhh. You throw rocks in curling not curls ;)

I should have made my argument pushing up a slight incline from point A to point B. Then we could have gotten rid of coasting.

You are right about the energy being tied up in rotation material in the hoop but is the energy proportional since it is dependent on velocity of the mass also.

If all that were true we wouldn’t have invented the wheel in the first place to overcome inertia and friction so that I could go get you guys for lunch for you only to find out I only have bunches of bananas at home to feed you.

[Fletcher]

Only a Canadian would know that ;7) I throw rocks in an argument, and at girls - I throw curly questions in a discussion ..

Your ride sounds like fun .. and banana's would be a step up for this monkey ..

So let's do a comparison ..

3 round objects (sphere, disk, and ring) of the same diameter and mass with the same friction coefficients for static and rolling, and there is no air drag .. we magically turn off all the frictions - we do a control experiment and we let them slide down the slope to the finish line - they do not roll .. all their linear inertia's are the same and they arrive with the same velocity and translational KE at the same time .. this total KE is the same as the PE they have lost ..

Then we turn on all the frictions and repeat the experiment - they have no slippage and this time they roll downhill and all arrive at different velocities and times - the times are longer than the control experiment and the velocities less - but they lost the very same PE we hear the crowd mumbling .. taking a large bite of my banana I wonder why, just because they were rolling they arrived at different times and velocities - I figure it must be because of the mass distribution about the center of rotation being forced to accelerate in a circle and resisting that .. I call it Moment of Inertia for rolling objects or circular/curved motion .. now, where did I throw that banana skin ..

[andyblues]

Here Fletcher hows this sound, if you have a heavy rotating weight in a tube and that tube rolls in a chamber would you still say the same thing ,my mind sees a moving mass inside a chamber holding rotational energy momentum better than just a solid weight rotating, the reason i think this is because the rotating weight in the tube rotates at the higher speed even when the chambers curves are slowing the weight adding its rotation momentum in the whole system and over all making the system more fluid ? i get your point about you only get out what you put in but if you have a reaction that causes rotation, could it be caught in this system and add up to captured momentum ,okay it might not run the wheel but i feel it could create more angles of motion from the reaction point , give me your thoughts and try and keep them simple for me please all the best Andy

[Fletcher]

Hey there Andy .. just dropping in briefly, I'll get back to yuh .. but it raises a very good question for anybody to answer ..

I just always assumed that KEt + KEr = Total KE - I know we can test for straight linear KE as a control experiment by sliding or dropping something from height, therefore I assume in a rolling situation the lack of velocity and KEt on arrival MUST BE the KEr component of the Total KE (PE lost) .. But could KEt + KEr > than PE (mgh) lost ? i.e. doing work experiments that prove the quantity of both add only to mgh lost ?

So does anyone know of an actual real-world experiment that proves and quantifies this KEr assumption of mine ? A yo-yo doesn't even work because you give it a spin at the start tho it will fall slow and regain most of its height (regain PE - mgh) ..

[Robinhood46]

Ahhhh. You throw rocks in curling not curls ;)

I should have made my argument pushing up a slight incline from point A to point B. Then we could have gotten rid of coasting.

You are right about the energy being tied up in rotation material in the hoop but is the energy proportional since it is dependent on velocity of the mass also.

If all that were true we wouldn’t have invented the wheel in the first place to overcome inertia and friction so that I could go get you guys for lunch for you only to find out I only have bunches of bananas at home to feed you.

I don't throw rocks, or curls. The only thing i throw regarding this sport, is myself, on the floor with laughter, because of how stupid it is. Or to put it another way, I'm not too familiar with the technical terms of this sport, because i have never paid a great deal of attention to it.
If you'd made the argument with a slight incline, this would have complicated things even more. We would have needed to find a way of jacking one side of Fletcher's frozen lake up, which wouldn't have been an easy task.

The way i see the difference between the energy involved in sliding or rolling discs, spheres and hoops, is that gravity causes them to slide, because of the lack of friction, therefore they will all arrive at the same time and with the same energy at the finish line. Everything is equal until friction is involved.
When friction between the objects and the inclined plane are turned on, gravity can no longer cause them to slide, because friction is too great. gravity then needs to cause the object to rotate, which is more effort because of the rotational acceleration of the object's mass. The different distributions of the mass, of each object, has the effect of how hard it is for gravity to cause rotation. The harder it is for gravity to cause rotation, the slower the rotational speed will accelerate and the slower the object will descend the inclined plane.
We don't get two goes at gravity, either it causes the mass to rotate, or it causes the mass to accelerate to the ground, it can't do both. Maybe, the force that is being used for one cannot "also" be used for the other, would be a better way of saying it.

[eccentrically1]

https://en.wikipedia.org/wiki/File:Roll ... nertia.ogv - most of the difference in time at the flag is due to getting the mass moving?

Bing AI:
Searching for: Rolling Racers - Moment of inertia
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The video you’re referring to, “Rolling Racers - Moment of Inertia”, is a simulation that demonstrates how an object’s moment of inertia determines its resistance to rotational motion12. In the simulation, four objects are placed on a ramp and left to roll without slipping. Starting from rest, each object experiences an angular acceleration based on their moment of inertia12.
The video "Rolling Racers - Moment of Inertia" demonstrates how an object's moment of inertia affects its rotational motion. Four objects on a ramp roll without slipping, and each experiences angular acceleration based on their moment of inertia.
Objects:
• Hollow spherical shell (red)
• Solid ball (orange)
• Ring (green)
• Solid cylinder (blue)
Each object's center of mass travels with speed v_cm = ωr, where r is its radius, and ω is its angular speed. Friction causes a torque, leading to rotation. For objects of the same radius, mass is irrelevant; the geometric distribution of mass, represented by the value of I_k^2, determines acceleration. Objects with larger I_k values accelerate more slowly, affecting the time it takes to reach the flag.

Due to they are all doing different speeds at the flag they all have different impacts at the flag. Correct or not correct?

That’s correct! The speed of an object at the bottom of the ramp (at the flag) depends on its acceleration, which is influenced by its moment of inertia. The moment of inertia, in turn, depends on the distribution of mass in the object. Therefore, objects with different mass distributions (and thus different moments of inertia) will have different speeds when they reach the flag. This means they will also have different impacts at the flag. The greater the speed, the greater the impact. So, yes, your understanding is correct.

[eccentrically1]

B's wheels accelerated quickly (sphere/disc-like) then slowed to a constant acceleration (hoop-like).