An iron sphere of mass 10 kg has the same diameter as an aluminium sphere of mass 3.5 kg. Both spheres are dropped simultaneously from a tower in a vacuum. When they are 10 m above the ground, they have the same __________________.

In a free fall, acceleration does not depend on the mass of the object.

Therefore, even though an iron sphere and the aluminium sphere have different masses, both will fall with the same acceleration due to gravity g=9.8m/s².

Momentum, Potential energy, and Kinetic energy depend on the mass of the body. Therefore, these quantities will be different for the iron ball and aluminium ball.

Therefore, only 'Acceleration' is the correct response.