Answer: a vector quantity.
Acceleration is a vector quantity.
Step-by-step explanation: In physics, acceleration is a vector quantity because it has both magnitude and direction. The length of the vector is its magnitude. So the magnitude tells you, how quickly velocity changes. If an object has a negative acceleration, the acceleration occurs in the opposite direction to the movement of the object. Newton's second law says that the acceleration of an object is proportional to the net result of all forces acting on the object and inversely proportional to its mass. The mass is a constant of each object that indicates how the velocity of the object varies with the application of force.
