With what acceleration will a ball submerged under water with a mass of 200 g and a volume

With what acceleration will a ball submerged under water with a mass of 200 g and a volume of 0.5 dm³ float if the drag force when the ball moves in water is 2N?

m = 200 g = 0.2 kg.

g = 9.8 m / s2.

Fcopr = 2 N.

V = 0.5 dm3 = 0.005 m3.

ρ = 1000 kg / m3.

a -?

3 forces act on the body:

gravity m * g directed vertically downward;

buoyancy force of Archimedes Farkh = ρ * g * V, directed vertically upwards;

resistance force Fsopr directed in the opposite direction of the movement, that is, vertically down.

Let’s find the resultant of all forces by the formula: F equal = Farch – m * g – Fcopr.

F equ = 1000 kg / m3 * 9.8 m / s2 * 0.005 m3 – 0.2 kg * 9.8 m / s2 – 2 H = 45 N.

According to 2 Newton’s laws: a = F equ / m.

a = 45 N / 0.2 kg = 225 m / s2.

Answer: the ball moves with acceleration a = 225 m / s2.