Answer :
The buoyant force acting on a ball completely submerged in water is calculated through Archimedes' principle and is found to be 10 Newtons.
To calculate the force of buoyancy on a ball when it is completely submerged in water, we apply Archimedes' principle, which states that the buoyant force on an object submerged in a fluid is equal to the weight of the fluid displaced by the object. Since the ball has a density of 4000 kg/m3, to find the volume of the ball, we use the formula for density (Density = Mass/Volume), thus Volume = Mass/Density. With the mass of the ball being 4 kg:
Volume = 4 kg / 4000 kg/m3 = 0.001 m3
The weight of water displaced can then be calculated with the water's density and the volume of the ball:
Mass of displaced water = Volume \\* Density of water = 0.001 m3 \\* 1000 kg/m3 = 1 kg
Finally, applying the buoyant force formula (Buoyant Force = Mass of displaced water \\* g), where g is the acceleration due to gravity:
Buoyant Force = 1 kg \\* 10 m/s2 = 10 N
Thus, the buoyant force acting on the ball is 10 Newtons.
