1. Net Force: The greater the net force acting on an object, the greater its acceleration. This is described by Newton's Second Law of Motion: F = ma (Force equals mass times acceleration). A larger force produces a larger acceleration, assuming the mass stays the same.
2. Mass: The smaller the mass of an object, the greater its acceleration for a given force. This is also part of Newton's Second Law. A smaller mass will accelerate more readily than a larger mass when subjected to the same force.
