Velocity is a vector quantity, possessing both magnitude (speed) and direction. Even though the car's speed (magnitude) is constant, its direction of travel is continuously changing as it moves along the circular track. Therefore, the car's velocity is continuously changing because its directional component is always varying. Why others are wrong: A — Velocity includes direction; a constant speed with changing direction means changing velocity. C — Velocity changes if either speed (magnitude) or direction, or both, change. D — The car is continuously in motion, so its velocity is never zero unless it stops.

Velocity is a vector quantity, defined by both magnitude (speed) and direction. Even though the satellite's speed is constant, its direction of motion is continuously changing as it follows a circular path. Therefore, the velocity, which includes direction, must also be constantly changing. Why others are wrong: A — This statement confuses speed with velocity; constant speed does not mean constant velocity if direction changes. C — The scenario states constant orbital speed, implying no increase in velocity magnitude over an orbit. D — The satellite is in continuous motion; thus its velocity is never zero unless it stops, which it does not.