The weight of a metal piece with a volume of 400 cm³ is 28.4N. What is this metal?

Given:

P = 28.4 Newton – the weight of a piece of metal;

g = 10 Newton / kilogram – acceleration of gravity;

V = 400 cubic centimeters = 0.0004 cubic meters – the volume of a piece of metal.

It is required to determine what kind of metal it is.

Find the mass of a piece of metal:

m = P / g = 28.4 / 10 = 2.84 kilograms.

Then the density of the metal is:

ro = m / V = 2.84 / 0.0004 = 7100 kilograms per cubic meter.

From the table of metal densities, we find that this density corresponds to zinc.

Answer: The piece is made of zinc.