A body with a density of 0.75 that of water floats in water. How much of the body’s volume is in the air?

Given:

p is the density of water;

p1 = 0.75 * p – body density depending on the density of water;

g is the acceleration of gravity.

It is required to determine V1 / V – what part of the body volume is in the air.

Let V – the total volume of the body, V2 – part of the volume of the body in water, V1 – part of the volume of the body in the air. Then, since the force of gravity is balanced by the buoyancy force of water, we have:

G = A;

m * g = p * V2 * g;

p1 * V * g = p * V2 * g;

p1 * V = p * V2;

0.75 * p * V = p * V2;

0.75 * V = V2.

Since V2 = V – V1, then:

0.75 * V = V – V1;

V1 = V – 0.75 * V = 0.25 * V or V1 / V = ​​0.25 (one quarter).

Answer: one fourth of the total body volume is in the air.