Final answer:
When a girl is running along a straight road with a uniform velocity of 1.5 m/s, her acceleration is zero because there is no change in her velocity over time.
Step-by-step explanation:
If a girl is running along a straight road with a uniform velocity of 1.5 m/s, her acceleration is zero. Uniform velocity implies that there is no change in speed or direction, which in turn means that there is no acceleration. Acceleration is defined as the rate at which an object's velocity changes over time. Since the girl's velocity is not changing, her acceleration is zero.