Okay, so this (theoretically, of course) means that it takes the same
-total- amount of energy to accelerate my car (or a wheel) from 0-20mph in
first gear as it does to go 0-20mph in fourth, right? I think I can
understand that, but still, something must give... it will take me -longer-
to get to 20mph in 4th than in 1st. The energy used is the constant, time is
the variable. If it took the same amount of time, we wouldn't need
transmissions.
However, when we're talking about accelerating drive and non-drive wheels
together, this means that time is constant relative to the two sets of
wheels. So, isn't there a difference in energy used, since time is now not a
variable?
Put another way: to accelerate from 0-20 mph in 4 seconds takes less energy
in 1st gear than it does in 4th gear. Isn't this correct?
Not trying to be argumentative, just making sure I understand this properly.
William Loring
> From: Alan Pozner <AlanP@identicard.com>
>
> What's wrong with the logic can be summed up by saying, "how you do the work
> has no effect on the amount of work done" In other words, the non drive
> wheels need to spin up to a certain speed just like the drive wheels. If
> both sets of wheels weigh the same then when they are at speed they will
> have the same kinetic energy. So it must have taken the same amount of
> energy to get them there (all other things being equal)
>
> Regards,
> Alan Pozner
>
>
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