The ball floats at a constant speed in the liquid, the density of the liquid is 4 times the density of the ball material

The ball floats at a constant speed in the liquid, the density of the liquid is 4 times the density of the ball material. Determine the force of resistance of a liquid when a ball moves in it, assuming it to be constant. Ball weight 10g

Given: m = 10 grams = 0.01 kilograms – the mass of a ball floating in water;

ro1 = 4 * ro2 – the density of water is 4 times greater than the density of the ball;

g = 10 m / s ^ 2 – acceleration of gravity;

V is the volume of the ball.

It is required to find Fс – the force of water resistance (Newton).

Since, according to the condition of the problem, the ball floats up with a constant speed, then according to Newton’s second law:

A – G – Fc = 0, where A is the Archimedean force, G is the force of gravity.

ro1 * V * g – m * g – Fc = 0;

Fc = ro1 * V * g – m * g;

Fc = ro1 * m * g / ro2 – m * g;

Fc = 4 * ro2 * m * g / ro2 – m * g;

Fc = 4 * m * g – m * g;

Fc = 3 * m * g = 3 * 10 * 0.01 = 0.3 Newton.

Answer: the resistance force of the ball is 0.3 Newton.