Answer:
D. All of the above.
Explanation:
Iron has a constant density, which means 2-kg block will have twice as much volume as 1-kg block; therefore, choice A is correct.
Inertia is defined by the equation F = ma: it measures how hard it is to change the motion of an object. The inertia of the the 1-kg solid iron is
F = 1a,
And the inertia of the 2-kg solid iron is
F = 2a,
which is twice as much that of the 1-kg block; therefore, choice B is correct.
The mass of the 2-kg block is twice as much as that of the 1-kg block; therefore, choice C is also correct.
Thus, all of the choices are correct (D).
