Quick Answers to small questions

[Souron]

Since there are several loads, you could just find out by experiment. Take the first load one way and the second load the other way and compare how exhausted you are after each of them. This isn't going to be a very accurate measurement, but it's way more accurate than a theoretic calculation would be.

Describing the effort of carrying something is quite difficult, because from the physics point of view, you're hardly doing any work at all, but due to the way muscles work, they will get exhausted nevertheless.

In the end the experiment is the deciding thing in science. It doesn't help, if one way should be easier on you, when you feel the other way afterwards.

Re physics: Yes, but there are statistics for calories burned from such activity.

Tiredness can be hard to compare when the activities have an unbalanced intensity, such as here where by the time you get off the subway, you may have already forgotten any tiredness felt from caring the load to the subway.

 

[uppi]

Re physics: Yes, but there are statistics for calories burned from such activity.

How do they get these and could we apply those method to this situation?

Tiredness can be hard to compare when the activities have an unbalanced intensity, such as here where by the time you get off the subway, you may have already forgotten any tiredness felt from caring the load to the subway.

It might be hard, but should be possible if the difference is large enough. If it's not, a more objective method might be needed. One option might be to measure the heart beat rate and then integrate the increase in heart beat rate over the time. That should result in a good estimate how much effort it was.

 

[Tabster]

Is doing the maths going to burn more calories than carrying the wood?

 

[Brighteye]

I'm a woodworker, and I save off-cuts to burn in the firepit in our back yard. But getting them home presents a problem. I have a car, but I don't like to use it unless absolutely necessary (I live in New York City). So I take several small loads each week. Sometimes I ride my bike, other times I use the subway. It occurs to me that one method may be easier on me than the other.

Are you carrying in a rucksack? It makes a huge difference over in your arms.
But either way, cycling ought to be better. It keeps you healthy.

It would have to be a very short distance for the underground not to be easier for you.
If we take efficiency figures, which will make it as accurate as we need, we see that cycling is 95% efficient and walking 25%. Now that walking figure comes from the first research paper that Google threw up, and is a combination of walking (27%) and stepping (20%)
The ratio is 19:5 so you need to be cycling three times as far as you'd be walking in order to make the underground worthwhile.

Yes, I've ignored possible differences caused by carrying wood, I've ignored recovery times whilst travelling and I've ignored the inefficiencies of the American 'let's put traffic lights everywhere to slow traffic down' system. But I think that there are more important concerns, like whether cycling is good for you and the planet.

 

[peter grimes]

...there are more important concerns, like whether cycling is good for you and the planet.

I agree
But I posted this question not because I want to know which is the better way to go (the bike, clearly!), but because I was simply curious about how the two trips compare energy-wise.

I'll post some actual distances and masses later on today if work eases up.

Oh - On the bike, I put the scraps in a canvas bag that's strapped to the rear deck, when I take the subway I use a backpack. So I suppose that we could simply assume that the mass of the wood is added to my own mass when walking; and added to the bike's mass when biking.

 

[Brighteye]

The thing is that we don't need to calculate actual energy expenditures. All we need are ratios. The way you're carrying the wood shouldn't make much difference to one method of travel over the other, and so we don't need masses of wood or peter grimes, because those are the same either way.
We just need what's different, and those are the efficiencies of the methods of travel and the distances.

If you really want energy expenditure, let's go with a weight of 1,200 N and a distance of 1,500m,
and using Google we get 150 KCal.

 

[peter grimes]

OK, I put all the details onto a googleMap

The bike route starts at City Center and ends at my apartment (5.95km). I detailed the incline and decline of the bridge (the lines parallel to the bridge, but separate from the route).

For the walking part, it's split up into 3 sections: From the shop to the train, a transfer underground, then from the second train to the apartment. I go up stairs for a total of 10m, down a total of 15. Flat walking is the rest of the way = 700m (total of 210 + 180 + 310)

 

[PlutonianEmpire]

Posted this in another thread, but since it's science related, I figured it might be better off in this thread/forum.

Do scientists / astronomers know the age of the Delta Trianguli star system? If so, what is it?

 

[Brighteye]

I'm sorry, Peter, but this is all a bit beyond me. I can say, though, that to get any more accuracy than the 75 KCal for the walking journey you'll need to consider your speed.
Cycling fast takes a lot more energy than cycling slowly. Accelerating does too, so if you have to stop and start you'll burn more energy.

Short of some very complex calculations using a sample journey in which you give us distances in metres and seconds taken (with incline covered), separated into periods of different acceleration, you'll be much better off using Google to find average energy consumptions for types of locomotion and plugging those into your distances.
You might be able to find some fancy gizmo to fix to your bike to measure your energy consumption. I have an exercise bike in the laboratory here, for example, on which I can finely control the wattage, and that gives me a good idea of my energy consumption when out and about.
You could also get one of those pedometer things that probably calculate energy consumption as they measure your steps.

 

[peter grimes]

This has all been pretty illuminating! I don't think I'm going to bother to go through all the required steps to figure it out... after all, it was an idle curiosity that first got me to wondering whether or not it even could be solved in the first place!

 

[Birdjaguar]

Is there a way to express a hydrogen atom in quantum mechanical terms or notation?

 

[ParadigmShifter]

A hydrogen atom?
Don't know much about 'em.
But answers you'll see
If you don't listen to me
'Cos I can't describe
This thread you should subscribe.

 

[Quackers]

2+2 = 4

Anybody? PS?

 

[Tabster]

put 2 billiard balls in an empty bag, shake the bag, add another 2 billiard balls, shake the bag again,(a bag is an old-fashioned adding machine) empty it out, count the balls, there should be 4.

hydrogen atom in quantum mechanical terms or notation

er, don't know if it helps, but the schrodinger equation describes the orbiting electron as a wave form.

 

[ori]

Is there a way to express a hydrogen atom in quantum mechanical terms or notation?

linky

 

[ParadigmShifter]

2+2 = 4

Anybody? PS?

Still spamming I see.

Here's Russell's proof that 1+1 = 2. Just amend it as appropriate

 

[Birdjaguar]

A hydrogen atom?
Don't know much about 'em.
But answers you'll see
If you don't listen to me
'Cos I can't describe
This thread you should subscribe.

Undoubtedly correct even if not as accurate as Ori.

linky

That gave my brain a real workout. My idea was to compare simple chemical equations with their equivalent quantum expressions. That appears to be a very messy proposition.

Maybe quark notation would be simpler

Proton = UUD
Neutron = UDD

 

[ParadigmShifter]

Hawkwind time!

Einstein was not a handsome fellow
Nobody ever called him Al [citation needed]
He had a long moustache to pull on, it was yellow
I don't believe he ever had a girl [inaccurate: he married a cousin I think]
One thing he missed out in his theory
Of time and space and relativity
Is something that makes it very clear he
Was never gonna score like you and me

He didn't know about Quark, Strangeness and Charm
Quark Strangeness and Charm (etc.)

 

[uppi]

That gave my brain a real workout. My idea was to compare simple chemical equations with their equivalent quantum expressions. That appears to be a very messy proposition.

Maybe quark notation would be simpler

Proton = UUD
Neutron = UDD

Compared to quarks and all the mess that comes with it, the quantum mechanical description of the hydrogen atom is extremely simple.

The problem with chemical equations is that they are extreme simplifications of what is really happening and thus can not easily compared to the quantum mechanical description of the process. Getting an accurate description of chemical processes is still ongoing research and by no means solved.

The hydrogen atom in quantum mechanics is simple enough, but once you move on to the hydrogen molecule the troubles already begin to start.

 

[Atrebates]

Perturbation theories *groan* hatehatehate