V stands for speed, unit: m/s, s stands for distance, unit: m, t stands for time, unit: S. Speed is a physical quantity describing the speed and direction of an object, which is defined as the ratio of displacement to the time taken for such displacement.
Properties of velocity
1. When the acceleration of an object remains constant, the object moves at a uniform speed. Such as free fall, flat throwing, etc. When the acceleration direction and magnitude of an object are on the same straight line, the object will move in a straight line at a uniform speed. Such as a vertical throwing motion.
2. Acceleration can be calculated by the change of speed and time, but the factors that determine acceleration are the resultant force F and the mass m of the object.
3. Speed is a vector, regardless of average speed or instantaneous speed. The only criterion to distinguish speed from speed is that speed has magnitude and direction, and speed has magnitude and no direction.