In real life, it is extremely difficult for an object to maintain a perfectly constant velocity, especially over long periods of time. This is due to various factors such as external forces, friction, air resistance, and imperfections in the object or its surroundings.
In the absence of any external forces or influences, an object with no friction or air resistance could theoretically move with a perfectly constant velocity. However, it is challenging to eliminate all external factors completely, and in practical situations, they will almost always come into play.
For example, even on a smooth surface, there may be small imperfections or variations in the terrain that can cause slight changes in the object's motion. Additionally, air resistance or drag will usually act on objects moving through a fluid medium, such as air or water, and can cause changes in velocity over time.
Furthermore, forces such as gravity or electromagnetic forces can act on objects and affect their motion. These forces can cause acceleration or changes in velocity, making it difficult to maintain a perfectly constant velocity.
In summary, while it is theoretically possible for an object to move with a perfectly constant velocity in idealized situations, in real-life scenarios, factors such as external forces, friction, and air resistance make it challenging to achieve and sustain a truly constant velocity.