Forces that act on an object as it move downwards in a liquid?

1. Buoyant force: This is the upward force exerted by a fluid on an object that is partially or fully submerged in it. The buoyant force opposes the weight of the object and helps to keep it afloat.

2. Gravity: This is the force that pulls the object downwards towards the center of the Earth. Gravity is responsible for the weight of the object.

3. Drag force: This is the resistance force exerted by the fluid as the object moves through it. Drag force opposes the motion of the object and slows it down.

4. Viscous force: This is a type of drag force that is caused by the viscosity of the fluid. Viscous force is proportional to the velocity of the object and the viscosity of the fluid.

5. Inertial force: This is the force that opposes the acceleration of the object as it moves through the fluid. Inertial force is proportional to the mass of the object and the rate of change of its velocity.

Gravitational Force:
- Acts downwards, pulling the object towards the center of the Earth.

Buoyant Force:
- Acts upwards, equal to the weight of the displaced liquid. It opposes the gravitational force.

Drag Force:
- Acts upwards or downwards, opposing the object's motion.
- If the object is moving downwards, drag acts upwards.
- If the object is moving upwards, drag acts downwards.

Additional Forces:

Viscous Drag Force:
- Acts in the direction opposite to the object's motion. It is caused by the viscous nature of the liquid.

Surface Tension Force:
- Acts on the object's surface, pulling it towards its center of curvature.
- In the case of a liquid drop, it causes the drop to form a spherical shape.

Magnus Force:
- Acts perpendicular to the object's direction of motion and to its axis of rotation. It is caused by the difference in pressure between the surfaces of the object moving at different speeds.