Quote:
Originally Posted by phuber
Regarding the first publication on "Advanced Technology Vehicle Modelling". I hate to question a .gov publication, but in equation (1) it says the mass is in tonnes, however the power is in Watts so I've a problem with the units, ie shouldn't the mass be in kg?
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No reason to 'hate to question a .gov' ... they are people to ... no body is perfect ... everybody can make mistakes.
As for the use of Tonnes vs kg ... While they showed us the form of the equation , they did not show us actual math they did ... both are units of mass ... 1 Tonne = 1,000 kg ... the question is weather they accounted for the conversion properly in the math they did ... but we don't know the math they did ... the general form of the equation is just a unit of mass ... it could been in mg as long as the math is still done correctly.
That having been said ... I will agree they probably should have written it differently ... even if they did weigh the vehicle itself in metric tonnes... as it is ... it could mislead a novice into doing the actual math incorrectly.
As you say with the power in Watts the conventional unit of mass to use is the kg.
However ... sense I don't see their numbers being off by 1,000 ... which would be easily noticeable ... I suspect , despite the poor wording , that they did the actual math correctly.