"The Natural Philosopher" wrote in message
...
tony sayer wrote:

8

Is there anything in it that on a bike the body weight is supported
whereas with walking that load has to be taken by the legs an I presume
uses some energy doing that.

No.

Funny most people get tired when standing some what faster than when they
are sitting.

I think you have managed to get the gold again, hell no, you get platinum.


Also a train is carried on its wheels, whereas an aircraft has to
support its own weight all the time?..

None of this is relevant really. There is a slight issue with the aircraft
in that it has to 'make up' the glide slope loss (as it were) all the
time, but with glider slopes of 20: or better, its not a big issue with
respect to the forward speed.

For example a light aiorcraft [eaks out about 50-70W per pound of weight,
but amnalusis shows a good aerodynamic plane can saty up with about
3-4W/lb - the rest goes in overcoming the drag.

Which is why airlines look pretty much like gliders - lowoest darg
possible

They don't look much like gliders to me.
You wouldn't get much fuel in the wing tanks if they did look like gliders.