What are the conditions for uniform velocity in the flight of a sugar glider?

[Taryn]

Hey I am just having a little trouble with understanding the diagram... i thought I knew wat to do but I seem to get it wrong and now I am confused... if you could help I would be very appreciative!
The diagram is on an attachment!


There are essentially three forces involved in flying: (i) ``lift'' Fl generated by the difference in air pressure between the top and bottom parts of a wing (or wing-like object), (ii) ``drag'' Fd due to air resistance, and (iii) ``gravity'' Fg. Note that ``lift'' is usually perpendicular to the flight direction while ``drag'' is directed in the opposite direction to flight.
These forces are involved in explaining the flight of aeroplanes, birds, flying foxes (bats), flying fish, sugar gliders, etc. Consider a sugar glider (petaurus breviceps) of mass m = 0.118 kg that is gliding from one tree to the next along a straight path at = 20.2o with respect to the horizontal as shown in the diagram. Assuming that there is negligible ``drag'', what is the magnitude of the ``lift'' force (in N)? Read more about sugar gliders here.

I know the answer is so simple... just has me stumped atm!

 

[Hootenanny]

Assuming that it is traveling with a uniform velocity; what are the conditions for uniform velocity?