This is fun!
For #1, my vote is B. 16%.
My reasoning: In a 30% bank, load factor is 1.154Gs, or just about 16% more than the weight of the glider in level flight. As bank angle increases, the lift vector is shifted into the turn and away from direct opposition to gravity. Assuming a constant angle of attack through the turn, effective weight exceeds total lift by 16%, which would subsequently increase the sink *rate* by about 16%,
For #2, my vote is C. 7.5%.
My Reasoning: We know that stall speed increases proportionally to the square root of the load factor. As far as I can tell, this effect should be universal for ALL performance airspeeds (excluding structural limitations like Va, Vra, Vt, Vw, and Vne) Since we’re in a 30 degree bank, we know our load factor should be 1.16, and the square root of 1.16 is 1.077, or just about 7.5% increase over the reference airspeed in the POH.
So, in practice a glider with a minimum skink speed of 40kts at max gross should expect to use 43kts for a 30 degree banked turn.
How’d I do? 🙂