scientifically minded people answer my question

[Tortington]

so, there was a thread like this before where people asked " how come the sky isn't really blue" and stuff

well my dd and i were talking about global warming yesterday in the car ( like you do!) and onto electric cars.

so, i wondered why the motion of a car itself doesn't or i mean can't create electicity to be stored in a battery enabling it to go quite fast and - are you still with me - therefore perpetuating its own power with every journey it makes.

then i got to thinking abotu curent hybrid cars and i dont get this..

so taking my perpetual force creating electricity theory above - i would think that with a hybrid car you would have to use gas to start the motion ( therefore creating the electicity) then run on electriciy - but it doesn't work that way i dont think - i certainly dont understand how electricity is used at slower speeds - when my way seems to make more sense.

so my questions are
why the motion of a car itself doesn't or can't create electicity to be stored in a battery enabling it to go quite fast and therfore perpetuating its own source of free power to be used?

and

taking the above question in account - how come hybrid cars use leccy at slower speeds not faster?

( am off all week, and i have been thinking!)

get back to work woman, you obv have far too much time on your hands.

Like the idea of the perpetual motion thing btw, in the same way that a car constantly powers the radio or fag lighter...

umm custy this isn't really my area but I think it has something to do with Friction, and the power needed to kickstart the old Kinetic energy.

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do you write exam papers for a living, custardo?

Friction and waste of energy in the form of heat energy.

All energy exchanges are ineffcient to a degree, heat energy making up part of the waste.

So for example when you run a car engine you turn the chemical energy stored in the Petrol (a potential energy) into Kinetic (movement energy) however there is enegy converted into sound energy and also heat energy.

And electric car (hybrid) will still have to 'top up' the 'wasted' energy IYSWIM.

Entropy mannnnnnnnn

respect, MB

Not even quite sure why I clicked on this

So a car cannot run on electricity alone? I take your point about wasted energy, but presumably that principle applies just as much to conventional petrol engines - why is electricity different?

mb. i have no idea what you just said. when you have some time and can be arsed with a stupid bored woman..imagine i am 7.

Energy can not be created or destroyed but is lost easily. The sort of car you are talking about using kinetic energy (energy created from movement) would only work if these energy losses were stopped, i.e. no heat generated by the engine, no friction, braking is a hige loss of energy - putting a lot of effort into stopping the tyres when all that fuel has been used to make the wheels turn in the first place. It would be almost impossible to make an efficient car with no energy losses.

With current technology, it is possible for a car to run entirly on electricity, but because of energy waste, the battery/generator needed would be very heavy which would be inefficient.

Hybrid cars work well because they only use electricity for slower speeds therefore need smaller battery/gnerator therefore the car is lighter and cheaper to run.

It will happen though, cars running on hydrogen would be where I'd place my money, clean technology and readily available.

why does heat from the engine interfere with the energy production/

i thought about the braking - and thats why i thught that it made more sense to get the car goign with gas to start the motion to produce the energy

whats hydrogen where does it come from?

so its really about inventing a storage facility for the kinetic ( i ued i science word!) energy which would be efficient?

OK. All energy exsists in two basic types.

Potential energy (which is kind of of 'stored' energy) for example energy stored in your food. Think of this like money saved in the bank if you like.

Kinetic (or moving) energy.....this is energy that is doing something...so for example sound energy (particles moving in the air), light energy. Think of this like money 'doing' something, being spent.

When you convert potential enrgy to kinetic energy (of whatever type) some of the enrgy is 'wasted' as heat energy.....like the bank taking its cut, if you like.

An example. When you use up your food to realise the enegy we need to live, heat is given off, some of the stored energy is wasted. When you push a block along a surface (cemical energy -> kinetic energy) the bottom of the block will heat up due to friction....and heat energy will be wasted.

No energy exchange is ever 100% efficient mostly due to friction.

Does that help? (PS I'm biologist as well)

hydrogen is an elemient....the lightest element and when it burns it gives out energy (explosive in fact!) and the by product is water H2O. Two hydrogen atoms and one oxygen bound together in a molecule of water.

Hydrogebn will give us a CO2 free fuel source, but we can't use it yet.

wow, i'm not a dumb-ass. I kinda knew martian's answer but was afraid to answer as I might be talking out my arse.

ethanol is getting me all excited at the moment.

wow, i'm not a dumb-ass. I kinda knew martian's answer but was afraid to answer as I might be talking out my arse.

ethanol is getting me all excited at the moment.

The third law of thermodynamics states that it's impossible to have a perpetual motion machine. The energy losses MB describes explains why.

Heat doesn't interfere with energy production, heat itself is an energy. So if one of the effects of running an engine is heat, and the heat isn't converted back into useable engery it is considered a waste or energy.

When you start your car, the petrol is ignited (tiny little explosions inside your engine). The force from these explosions drives the car but heat is obviously also made when setting fire to the petrol. This heat not only a waste of the energy needed to run the car but more energy from the car has to be used to keep the engine cool, i.e. powering a radiator.

hydrogen used in hydrogen engines comes from water. The chemical symbol for water is H2O i.e. two parts hydrogen, one part oxygen. The waste products from a hydrogen engine are, I think, just oxygen so it's called a clean fuel. I'll check that bit out.

\link{http://www.planet-science.com/home.html\Planet Science} is a good place to start when your little ones ask those tricky questions..(there's stuff for parents and teachers too)

you got there before me.

DC, ethanol always gets me excited too, but that is a different thread!

Ethanol is only CO2 neutral though.

you can get arrested for getting excited over that daddycool.

so when you transform kinetic energy into a form that can be used - heat is the by product? is that always the case? is that how my electric fire gives me heat? or is that something else entirely!

so lets make this my supercar... i start it up - using gas. it gets going and starts creating enough energy to power itself. however we have not discovered a great way of storing this energy and disposing of the by-product which is heat. and there would be a lot of heat.

is that right.

ok now hydrogen.
is just a thing that exists already is it - like errr carbon or oxygen?

and is it that the energy used to overcome the heat (a cooling system) would cancel out the benefits of the kinetic energy.

am getting a bit confused now - i need a brew.

custardo,

whenever you transfer energy from one form to another you waste some (usually as heat)
you need energy to speed up your car which you might get from gas, petrol, battery, whatever
you can get some energy back when you slow it down but you'll always have lost some along the way
so you'll end up with less energy than you start with

your electric fire converts electric energy into heat energy
my little fiat punto converts chemical energy (in petrol) first into kinetic energy (me moving), then into heat (in the brakes when it slows down)

it's all about changing energy from one form into another ...

(going back to lurking now)

i asked my dh this last night - he just shrugged.

think he couldn't be arsed with me becuase i'm as thick as pig shit. so thanks for baring with me

electric fire - heat isn't the byproduct becasue heat is what you want from it, but it isn't efficient as it uses a lot of electricity to produce this heat in comparison to how much electricity other appliences use.

You are transforming potential energy (petrol) into kinetic energy (moving the car). Heat is not needed so is considered a byproduct. If a way could be found to use convert this heat into kinetic energy then a car would be a lot more efficient.

Rotting organic matter produces hydrogen, you could run a hydrogen car on your kitchen waste.

picture this, you start up you super car on your potatoe peelings, the byproducts of using this hydrogen are water and heat (I just looked it up). As the fuel is readily available then there is no need to try to create a system with no products.

Now here's a discussion, hydrogen fuel cells are developed but because of political pressure they are not widely used. Oil companies don't want their profits to disappear if people could supply their own fuel.

bless my typing. sorry.