Acceleration refers to the rate of change of an object's velocity. It is a vector quantity, meaning it has both magnitude (size) and direction.
Acceleration is typically measured in units of meters per second squared (m/s²). This represents the change in velocity (in meters per second) over a certain amount of time (in seconds).
Speed refers to the rate at which an object is moving, while acceleration refers to the rate at which an object's speed is changing. In other words, acceleration is the change in speed over time.
The formula for acceleration is a = (v₂ - v₁) / t, where a is acceleration, v₂ is the final velocity, v₁ is the initial velocity, and t is the time interval.
The direction of acceleration is determined by the direction in which an object's velocity is changing. If an object's velocity is increasing, the acceleration is in the same direction as the velocity. If an object's velocity is decreasing, the acceleration is in the opposite direction as the velocity.