What is the density of a body if it weighs 2.7 N in water and 3 N in air?

Let us determine what the force pushing a given body out of water will equal, when from the condition of the task we know that in air the body weighs 3 N, while in water it weighs 2.7 N:

3 – 2.7 = 0.3.

Let’s determine how much water this body displaces when we know that the density of water is roughly 1000 kg / m3:

V * 1000 * 10 = 0.3;

V = 0.00003.

Let us determine what the density of the body will be equal to, because its volume is equal to the volume of the liquid that was displaced:

3 = 0.00003 * 10 * p;

p = 10000.

Answer: 10,000 kg / m3.