On a distant planet the acceleration due to gravity is 20m/s2. A stone is dropped from rest. Compared with the velocity–time graph of the same experiment on Earth (g=10m/s2), the new graph will be
a) A straight line through the origin with the same slope as on Earth
b) A straight line through the origin with double the slope
c) A straight line through the origin with half the slope
d) A parabola opening upward through the origin