Two bodies of the same volume are made of aluminum and iron. Find the force of attraction

Two bodies of the same volume are made of aluminum and iron. Find the force of attraction of an aluminum body to the Earth, if the mass of an iron body were 7.8 kg.

Given:
V1 = V2 – the volumes of aluminum and iron are equal;
m1 = 7.8 kilograms – iron body weight;
ro1 = 7800 kg / m3 – iron density;
ro2 = 2700 kg / m3 – density of aluminum;
g = 10 m / s2 – acceleration of gravity.
It is required to determine F (Newton) – the force of gravity acting on a body made of aluminum.
Since the volumes of bodies are equal, we find the volume of a body made of iron:
V = V1 = V2 = m1 / ro1 = 7.8 / 7800 = 0.001 m3.
Then the mass of a body made of aluminum will be equal to:
m2 = V * ro2 = 0.001 * 2700 = 2.7 kilograms.
The force of gravity will be equal to:
F = m2 * g = 2.7 * 10 = 27 Newtons.
Answer: a gravity force equal to 27 Newtons acts on an aluminum body.