# Two aluminum balls have the same volume, but one is hollow and the other is solid, can you use the

**Two aluminum balls have the same volume, but one is hollow and the other is solid, can you use the Archimedean force to determine which one is hollow? And which one is solid?**

A buoyant force equal to the weight of the displaced fluid acts on a body immersed in a liquid, and is called the Archimedes force:

Fa = ρ * g * V, where ρ is the density of the liquid, g is the acceleration of gravity of a body raised above the Earth g = 9.8 m / s², V is the volume of the body.

In our case:

Fа1 = Fа2

The body under the action of gravity presses on the water with the force of gravity:

Fт = m * g

The force of gravity does not depend on the volume of the body, but on the mass; a hollow sphere has less mass than a solid one.

Ft1 <Ft2

According to Newton’s second law:

Fт-Fа = ma

Their expression shows that the greater the gravity (mass) of the body, the faster it will sink.

Answer: If both balls are thrown into a liquid, then the solid ball will sink faster.