Acceleration is the rate of change in the velocity of an object with respect to time. Accelerations are vector quantities (which have magnitude and direction). The direction of the acceleration of the object is determined by the direction of the net force acting on the object. The magnitude of the acceleration of an object, as defined in Newton’s Second Law, is the combined result of two causes:
- The total amount of all external forces acting upon the object — magnitude is directly proportional to the corresponding net force.
- The mass of the object, depending on the components it is made from — the value is inversely proportional to the mass of the object.
Metre per second squared is the SI unit for acceleration.