If the mass of an object is doubled what happens to the acceleration of that object?
It would depend on what force is driving the acceleration. If
that force is gravity, then acceleration is constant irrespective
of variations in mass. All else being equal and presuming the
acceleration is by the same exerted force on both the larger and
smaller object, the larger object would experience 1/3 the
acceleration. (The formula for determining the force is F = ma ,
the mass times the acceleration. For the same F, and m2 is 3m, then
a2 must equal a/3. )