On Oct 31, 4:20*pm, Udo wrote:
Here are the data points for glider A:
starts at exactly 13 minutes and 42 seconds.
at 2349 ft with a speed of 50 kt

arrives at 20:22 at the finish line with an
altitude of 121 ft at 95 kt, a distance covered of 12.7 miles.

Glider B
starts at nearly the same location ( within 100 ft) at 13:56
at an altitude 2400 ft at 57 kt

arrives precisely at the same finish line at 20:02
at an altitude of 62 feet with a speed of 103 kt also covered the same
distance of 12.7 miles.

*The condition are the *same but for the second glider leaving 14
seconds later and arriving 20 seconds *early. The flight pass was
nearly identical but for the second glider passing the first
hal ways

What is the true difference between the two. It is clear there is not
much difference.

Thanks in advance for shedding light on this for me.
Udo

Udo,

Assuming (OK, we know what that means) that both gliders are at the
same weight and the same performance. If they were not that could be
a big difference.

Glider B had 3.77% more energy expended than glider A from the start
to finish just in a total energy balance but this does not account for
all the 9.29% better speed. About 5.5% of the better speed has to be
accounted for from picking a better line, flying at better speeds at
the right time, better performance of the glider, and weight
difference.