The motion of an object is determined by the sum of the forces acting on it; if the total force on the object is not zero, its motion will change. The greater the mass of the object, the greater the force needed to achieve the same change in motion. For any given object, a larger force causes a larger change in motion.
Source: Why don't we fall into the center of the earth? [Advertisement]. (2017, March 2). Retrieved January 18, 2018, from https://www.youtube.com/watch?v=QMpYOW8fpl8