1. Gravity (Fg): This force pulls the ball downwards, towards the center of the Earth. Its magnitude is calculated as:

* Fg = mg, where:

* m is the mass of the ball

* g is the acceleration due to gravity (approximately 9.8 m/s²)

2. Buoyancy (Fb): This force acts upwards, opposing the force of gravity. It is caused by the pressure difference between the top and bottom of the ball, which arises from the weight of the water displaced by the ball. Its magnitude is calculated as:

* Fb = ρVg, where:

* ρ is the density of the water

* V is the volume of the ball submerged in water

* g is the acceleration due to gravity

3. Drag (Fd): This force opposes the motion of the ball through the water and acts in the opposite direction of the ball's velocity. It is caused by the friction between the ball's surface and the water molecules. The magnitude of drag depends on factors like the ball's shape, size, velocity, and the viscosity of the water.

4. Weight of the ball (W): This is the force exerted by the ball due to its own mass. It's essentially the same as the force of gravity acting on the ball.

Here's how these forces work together:

* When the ball is sinking, the force of gravity is stronger than the force of buoyancy. This means the net force acting on the ball is downwards, causing it to accelerate downwards.

* The drag force will increase as the ball's velocity increases. Eventually, the drag force and the force of buoyancy will balance the force of gravity, causing the ball to reach a constant sinking velocity (terminal velocity).

It's important to note that the exact magnitude of each force will depend on the specific properties of the ball (like its mass, volume, and shape) and the water (like its density and viscosity).