text: why is this statement correct? "the more the massof an object, the more force needed to move it".? explain in scientific terms please ... force = mass times weight.  on earth the mass is constant, because the gravitational pull is constant.  so the amount of force needed to move an object that is at rest, depends upon the mass.  in other words the heavier the object, the more force needed begin motion.  however!.....there is one more factor that is neglected by the above equation.  newton, tended to do that, most of his laws only apply in a vacuum and on frictionless condition.  that other factor is the coefficient or friction. on ice its low...and take less force to set an object into motion. on sand paper the coefficient is high!  recap! heavier objects on rougher (higher coefficient of friction) surfaces are more difficult to set into motion.  good luck!