Two identical carts A and B start from rest on smooth tracks of different heights. Cart A descends through a vertical height of 1.5 m, while cart B descends through 3.0 m.
Take g=10m/s2.
a. (i) Find the ratio of their speeds at the bottom of their respective tracks (vA:vB).
b. (ii) Give one reason for your answer based on energy considerations.