Newton's Second Law
If an object was to move with constant velocity, would there be any external force exerting on it? No, according to Newton's Second Law, an object will move with constant velocity until a force is exerted on the object. Or from a different angle, force effects acceleration. Newton's Second Law basically tries to explain the relationship between force and acceleration. What is this relationship?
Force = mass * acceleration
As force increases, acceleration will increase at a proportional rate.
But the equation also explains the relationship between force and mass.
If you push two objects of different masses with the same force,
the object that is lighter will have greater acceleration.
Or from a different perspective,
if two objects of different masses are accelerating at the same rate,
the more massive object has a greater force exerting on it.
To summarize all these relationships in mathematical terms:
Acceleration is directly proportional to Force and inversely proportional to mass.