Final answer:
Speed that does not change is referred to as constant speed or uniform speed. It is a scalar quantity, indicating magnitude only, and uniform motion involves maintaining the same velocity, including both speed and direction.
Step-by-step explanation:
Speed that does not change is referred to as constant speed or uniform speed. When an object is moving at constant speed, it covers equal distances in equal intervals of time regardless of the direction of motion. Speed, being a scalar quantity, is only concerned with magnitude, not the direction of the travel.
Motion at a constant velocity, or uniform motion, means that the position of the object is changing at the same rate over time, and this typically indicates that there are no changes in speed and direction – the velocity is consistent. However, when referring specifically to speed without direction, constant or uniform speed can occur even if the direction changes.