Answer:
As a wire gets longer its resistance increases, and as it gets thinner its resistance also increases because its cross sectional area decreases. Doubling the length will double the resistance, but the wire also must get thinner as it is stretched, because it will contain the same amount of metal in twice the length.
Sphere A travels a horizontal distance of (10 m/s) <em>t</em> after time <em>t</em>, while sphere B travels a distance of (5 m/s) <em>t</em>. So sphere B lands on the floor some point between the table's edge and the point X (A).