Mr.Clutch?

[Fredxxx]

Quite, but do you know the answer to Peter's question?

[Dave Plowman (News)]

Do you never read or understand anything?

A BMW 530d is a diesel. A 530i a petrol. The cars don't have the same gear ratios or even weight. Making comparison pointless.

I thought even you understood that a gearbox multiplies torque.

[Fredxxx]

Yes, thanks. I even understand the question and know the answer. You don't.

Are you now saying a car accelerates more or less depending on whether they are fuelled by diesel or petrol?

Quite, so which is accelerating the most?

Simple question for which there is a simple answer. You don't need to know anything about box ratios, or torque or fuel type. Simple physics and mechanics.

[steve robinson]

I would think the answer to that would be yes if comparing 530 d versus 530i , the vehicles are different weights have a different gearing structure and a different power and torque curve based on the energy released from the differing types of fuel when its combusted at different rpms , petrol engines in theory can run at very high rev's desiels on the other hand would struggle when pushed past 5500 because of the atomisatrion of the fuel

[Fredxxx]

You're making too much of this. The power output takes into account things like fuel and atomisation etc.

The question was: Which car is accelerating the quickest and which gear does it accelerate quickest in? The one with more power or the one with more torque?

Lets assume the weights are the same, they're not much different in any case.

Come on Steve. Lets have the answer. It's very simple.

[Dave Plowman (News)]

We can now add in overall gearing to the vast amount of things you don't understand.

You do realise what a fool you are making of yourself?

[Fredxxx]

No, you are by not answering the simple question.

Do you understand that an increase in a car's speed requires an increase in kinetic energy?

[michael adams]

And the kinetic energy of a stationary vehicle is what exactly ?

michael adams

...

[tabbypurr]

[Fredxxx]

Are you drunk, high on something, or is that a serious question?

[michael adams]

It's a serious question

It was posted in response to this claim of yours.

Which for some reason you chose to snip.

So I can only ask you again

And the kinetic energy of a stationary vehicle is what exactly ?

michael adams

...

[Roger Hayter]

If you have no apples is there any particular problem in increasing the number of apples you have? Compared with already having some apples. I can see that negative apples would create a problem, but not one that a vector quantity would share. For aeroplanes in particular, acceleration in one direction may be necessary despite velocity being in another. The behaviour of kinetic energy in this case is harder to calculate, but follows rules.

[michael adams]

Not if the apples can self generate, no.

(Which is equivalent to applying Fred's definition to a stationary vehicle)

It might be the foundation of a very profitable business in fact.

But otherwise it would require an outside agency to provide the apples.

michael adams

...

[tabbypurr]

need one say more

[Robin]

I assume he has in mind the way

dv/dt=p/(mv)

begs the question "does this mean you get infinite acceleration when the vehicle is stationary"? And I assume he is looking for the answer "no because the *useful* power delivered is also nil when the vehicle is stationary".

I do not know if he is deliberately trolling by starting a new thread without quoting the relevant preceding post(s) or just striving to be seen as too clever by half.

[tabbypurr]

Having read Michael before I doubt he has put a moment of thought into either point. Or any other.

NT

[michael adams]

I'm simply asking Fred a simple question.

I can only say I'm sorry if my doing this upsets you so much that you feel you the need to comment; but there's not that much else I offer you by way of reassurance, I'm afraid.

Who would have thought that one simple question could cause so much fuss ?

michael adams

...

[Roger Hayter]

If you accelerate a moving car in the direction of its motion, its kinetic energy increases. If you accelerate a stationary[1] car, it acquires kinetic energy. I think I am missing the problem.

[1] Stationary only in our local frame of reference, of course, but that has no relevance at the sort of speeds we are talking about.

[Roger Hayter]

We are also talking about cars, and we know that in practice moving off from stationary is a rather discontinuous process. But it is also true that in any real car the acceleration at low speed is very much limited by the traction the tyre can achieve rather than the power the engine can produce. So the usable torque will be equivalent to quite low engine power. Drag racing is another issue. It was unwise to stray from the 60mph.

[Bill Wright]

"Hey Gavrilo, I'm bored. Fancy coming out and taking a few pot shots at the Archduke Ferdinand?"

"Have you put on a bit of weight darling?"

"Fancy one for the road?"

"Fancy a quickie?"

Bill