Martin Eiler wrote:

Here are two simple questions. The glider is an ASK-21
and for both questions the wind conditions are a smooth
steady 25 knots with no wind shear or gradient.

1. The pilot is holding North on his compass and the
glider is trimmed for 43 knots. He has a 90 degree
right cross wind from the East. The pilot then releases
the controls to see what the glider will do.
Do you believe the glider will turn into the wind,
downwind or stay facing North?

Ah geez. Is this a troll? I'll bite.
The glider will maintain its nnw ground track with the yaw string
straight back. duh!

2. The pilot next decides to practice stalls upwind and
downwind to find out if they are the same other than
the groundspeed.
Will he or should he notice any difference?

Depends. Is the sun out or is it overcast? Serious(er) his ground
speed is different heading east and west. This would be noticeable if
he looks for it. More noticeable at lower altitudes.

Talk to your instructor more about this subject. Its important to your
safety that you have a good understanding. Usenet is not the best place
to learn about wind speed, relative wind, shear etc. "Stick and
Rudder" by Lanngewieche would be a good resource, as would Tom Knauff's
books. (Unless Tom wants to reply directly but that doesn't sell books ;-)

Shawn