Which straight away should have alerted me to some sort of chicken-up, as it implies a deceleration to the car of 80g, which is a little severe...
I've not got time now to post a more carefully thought out set of calculations, but I will do so later. Some mental arithmetic suggests that, using some gentler numbers, the car may see something of the order of 4g, the lorry perhaps 1-30th of that, but I still consider that ought to be noticeable(*), as it represents a force perhaps double that which the engine could produce if it suddenly went to full power. I think I have also convinced myself that only the driving wheels can exert any sensible counter-force which might act to transfer momentum to the earth instead, but this would rely entirely on the engine being able to produce a braking force also in excess of the power it can generate under load. Cab suspension may indeed dampen the effect on the driver, but I suspect most of the free movement is in the vertical plane for shock-absorption, not fore-and-aft. To consider the trailer and tractor chbuttes as elastic is stretching credulity.
(*) However, if our friend who cannot find "momentum" in the dictionary is typical, perhaps not. It's somewhere between mock and moron, if that helps.
Cruise Control dangerous 5268somewhere. than you I think you're looking at the lorry & car as an isolated system, in which case you are perfectly correct in your buttertion of conservation...
Curious that this group seems to be populated with those who believe torque and power are somehow independent enbreasties, when they are not, as well as those who think momentum and energy are interchangeable, when again the opposite is true. (And some poor souls who fail on both counts, no doubt.)
-- Tried to play my shoehorn... all I got was footnotes!
Cruise Control dangerous 5270Nope, there have been numerous incidents of cars running into stationary lorries and the lorry driver not being aware. Even a vehicle with a lesser weight difference such...
Mail john rather than nospam...
