Lab 6: Newton's Second Law Objective Investigate Newton's second law of motion. Introduction Newton's second law states that the acceleration, a . of an object is directly proportional to the resultant force, F, acting on it and inversely proportional to its mass, m. If the mass of the object is constant, the net force equals the product of the mass and its acceleration. Thus, Fox = ma The acceleration, a , when uniform, can be calculated by the following equation of motion: d = vit - ar 2 where, /, is the time during which the object moves a displacement, d and v, is its initial velocity. If the mass starts from rest, the equation reduces to